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Hindawi Publishing CorporationJournal of Applied MathematicsVolume 2013 Article ID 848163 4 pageshttpdxdoiorg1011552013848163
Research ArticleA Note on Four-Dimensional Symmetry Algebras andFourth-Order Ordinary Differential Equations
A Fatima1 Muhammad Ayub2 and F M Mahomed1
1 Centre for Differential Equations Continuum Mechanics and Applications School of Computational and Applied MathematicsUniversity of the Witwatersrand Johannesburg 2050 South Africa
2 Department of Mathematics COMSATS Institute of Information Technology Abbottabad 22060 Pakistan
Correspondence should be addressed to A Fatima emanfatima81yahoocom and F M Mahomed fazalmahomedwitsacza
Received 12 November 2012 Accepted 24 December 2012
Academic Editor Mehmet Pakdemirli
Copyright copy 2013 A Fatima et alThis is an open access article distributed under theCreativeCommonsAttribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
We provide a supplementation of the results on the canonical forms for scalar fourth-order ordinary differential equations (ODEs)which admit four-dimensional Lie algebras obtained recently Together with these new canonical forms a complete list of scalarfourth-order ODEs that admit four-dimensional Lie algebras is available
1 Introduction
The integrability of scalar ordinary differential equations(ODEs) by use of the Lie symmetry method depends ontheir symmetrical Lie algebra if the Lie algebra is solv-able and of sufficient dimension There exists two differentapproaches to the integrability of differential equations usingLie point symmetries One is the direct method in whichLie point symmetries are utilized to perform integrability bysuccessive reduction of order of the equation using idealsof the algebra The other approach is the canonical formmethod if the equations are classified into different typesaccording to the canonical forms of the corresponding Liealgebra
Lie [1] classified scalar second-order ODEs into fourtypes on the basis of their admitted two-dimensional Liealgebras and also performed integration of the representativeequations corresponding to the canonical forms of the two-dimensional symmetry algebra Therefore scalar second-order ODEs can be integrated by using canonical variableswhichmap the symmetry generators to Liersquos canonical formsAlso here one can use successive reduction of order by usingideals of the symmetry algebra (see eg Olver [2]) TheNoether equivalence approach for Lagrangians correspond-ing to scalar second-order ODEs is discussed in Kara et al[3]
The canonical forms for scalar third-order ODEs thatadmit three symmetries were obtained by Mahomed andLeach [4] Then Ibragimov and Nucci [5] provided the inte-grability of these canonical forms
In their paper Cerquetelli et al [6] constructed realiza-tions in the plane of four-dimensional Lie algebras listed byPatera andWinternitz [7]Moreover the classification of sub-algebras of all real Lie algebras of dimensionle4was discussedin [7] The construction of Cerquetelli et al [6] was basedon the three-dimensional subalgebras provided in [7] Theyinvoked the realizations of three-dimensional Lie algebrasin the plane derived earlier by Mahomed and Leach [8] forthis purpose They then determined the fourth-order ODEsadmitting the realizations of the obtained four-dimensionalalgebras as their Lie symmetry algebra Finally they providedthe route to the integration of the classified fourth-orderODEs However the derived realizations of four-dimensionalLie algebras need supplementation in the light of recent workby Popovych et al [9] Recently these authors constructed acomplete set of inequivalent realizations of real Lie algebras ofdimension not greater than four in vector fields in the space ofan arbitrary (finite) numbers of variables We use the resultsof [9] to complete the classification of fourth-order ODEs interms of their four-dimensional algebras presented in [6]
Apart from scalar fourth-order ODEs arising in thesymmetry reductions of partial differential equations such as
2 Journal of Applied Mathematics
the linear wave equation in an inhomogeneous medium (see[10]) they occur prominently as model equations in the formof the static Euler-Bernoulli beam (see eg [11]) and Emden-Fowler equations Such equations have been investigated forsymmetry properties in [12 13]
Firstly we provide a comparison of the results of [9] andthat of [6] related to the realizations of four-dimensional Liealgebras as vector fields in the plane Then we list the newcanonical forms of scalar fourth-order ODEs which possessfour-dimensional algebras
2 Comparison of the Results of [6 9]
We show here that the results on realizations of four-dimensional algebras in the plane given in [6] are a specialcase of the corresponding set of realizations given in [9] Wemake a comparison of the lists of realizations given in [6]and [9] It should be remarked that in general a result ofclassification of realizations may contain errors of two typesnamely
(i) missing of some inequivalent cases and(ii) mutually equivalent cases
In the following comparison some first type of errorsexist in [6] Five cases are missing There are some othercases which can be combined in a compact form and alsosome arbitrary parameters and functions need modificationaccording to the results of [9] related to realizations in theplane Below we keep the notations of both on the left handside the notations of [6] and on right hand side that of [9]However for the final results and further utilization we keepthe notations of [9]
21 Four-Dimensional Algebras We use the nomenclature ofPatera and Winternitz [7] in the naming of the algebras suchas 4119860
1Thuswe do not provide a table of the abstract algebras
of dimension four as this is easily availableHere the 119873119906 refers to the realizations given in the work
[6] and 119877 to that of [9]
(i) 119873119906(41198601) sim (4119860
1) (1198901= 1198902 1198902= 1198903 1198903= 1198901 1198904= 1198904)
119873119906(41198601) sim 119877(4119860
1 11) (119905 = 119910 119909 = 119909)
(ii) 119873119906(1198602oplus21198601) sim (119860
21oplus21198601) (1198901= 1198902 1198902= minus1198901 1198903=
11989031198904= 1198904) No realization exists in (1+1)-dimension
(iii) 119873119906(21198602) sim (2119860
21) (1198901
= 1198902 1198902
= minus1198901 1198903
= 1198904
1198904= minus1198903)
119873119906(21198602) sim 119877(2119860
21 5) (119905 = 119909 119909 = 119910) whereas
119877(211986021
7) is missing in [6](iv) 119873119906(119860
31oplus1198601) sim (119860
31oplus1198601) No realization exists in
(1 + 1)-dimension(v) 119873119906(119860
32oplus 1198601 119891(119909) = 0) sim (119860
32oplus 1198601)
119873119906(11986032
oplus 1198601 119891(119909) = 0) sim 119877(119860
32oplus 1198601 9) (119905 = 119910
119909 = minus119909)
(vi) 119873119906(11986033
oplus1198601) sim (119860
33oplus1198601) No realization exists in
(1 + 1)-dimension
(vii) 119873119906(11986034
oplus 1198601 119891(119909) = 0) sim (119860
119886
34oplus 1198601 119886 = minus1)
119873119906(11986034
oplus 1198601 119891(119909) = 0) sim 119877(119860
119886
34oplus 1198601 9 119886 = minus1)
(119905 = 119910 119909 = 1199092)
(viii) 119873119906(119860119886
35oplus1198601 0 lt |119886| lt 1 119891(119909) = 0) sim (119860
119886
34oplus
1198601 |119886| le 1 119886 = 0 plusmn1)
119873119906(119860119886
35oplus 1198601 0 lt |119886| lt 1 119891(119909) = 0) sim 119877(119860
119886
34oplus
1198601 9) (119905 = 119910 119909 = 119909
1minus119886)
(ix) 119873119906(11986036
oplus 1198601 119891(119909) = 0) sim (119860
119887
35oplus 1198601 119887 = 0)
119873119906(11986036
oplus 1198601 119891(119909) = 0) sim 119877(119860
119887
35oplus 1198601 8 119887 = 0)
(119905 = 119910 119909 = (1199092minus 1)12
)
(x) 119873119906(119860119887
37oplus1198601 119887 gt 0 119891(119909) = 0) sim (119860
119887
35oplus1198601 119887 gt 0)
119873119906(119860119887
37oplus 1198601 119887 gt 0 119891(119909) = 0) sim 119877(119860
119887
35oplus 1198601 8
119887 gt 0) (119905 = 119910 119909 = 119909)
(xi) 119873119906(11986038
oplus 1198601 119891(119909) = 1) sim (Sl(2R) oplus 119860
1) (1198901= 1198901
1198902= 1198902 1198903= minus1198903 1198904= 1198904)
119873119906(11986038
oplus 1198601 119887 gt 0 119891(119909) = 1) sim 119877(Sl(2R) oplus
1198601 9) (119905 = 119910 119909 = 119909) whereas 119877(Sl(2 R) oplus 119860
1 8))
is missing in [6](xii) 119873119906(119860
39oplus 1198601) sim (So(3) oplus 119860
1) No realization exists
in (1 + 1)-dimension(xiii) 119873119906(119860
41 119891(119909) = 0) sim (119860
41)
119873119906(11986041
119891(119909) = 0) sim 119877(11986041
8) (119905 = 119910 119909 = 119909)
(xiv) 119873119906(119860119887
42 119887 = 0 1) sim (119860
119887
42 119887 = 0 1) (119890
1= 1198901 1198902= minus1198902
1198903= minus1198903 1198904= 1198904)
119873119906(119860119887
42) sim 119877(119860
119887
42 8) (119905 = 119890
(119887minus1)119909119910 119909 = 119890
(119887minus1)119909)
(xv) 119873119906(1198601
42) sim (119860
119887
42 119887 = 1) No realization exists in (1 +
1)-dimension(xvi) 119873119906(119860
43 119891(119909) = 0) sim (119860
43)
119873119906(11986043
119891(119909) = 0) sim 119877(11986043
8) (119905 = 119910 119909 = 119909)(xvii) 119873119906(119860
44 119891(119909) = 0) sim (119860
44)
119873119906(11986044
119891(119909) = 0) sim 119877(11986044
7) (119905 = 119910 119909 = 119909)
(xviii) 119873119906(119860119886119887
45 minus1 le 119886 lt 119887 lt 1 119886119887 = 0) sim (119860
119886119887
45 minus1 le
119886 lt 119887 lt 119888 = 1 119886119887119888 = 0) (1198901
= 1198902 1198902
= 1198903 1198903
= 1198901
1198904= 1198904)
119873119906(119860119886119887
45 minus1 le 119886 lt 119887 lt 1 119886119887 = 0) sim 119877(119860
119886119887
45 7 minus1 le
119886 lt 119887 lt 119888 = 1 119886119887119888 = 0 119887 gt 0 if 119886 = minus1) (119905 = 119909119886minus1
119910 +
119909119886 ln(1|119909|) 119909 = ln |119909|)
(xix) (119860119886119886
45 minus1 le 119886 lt 1 119886 = 0) sim (119860
11119886minus1
45 minus1 le 119886 lt 1
119886 = 0) (1198901
= 1198903 1198902
= 1198902 1198903
= 1198901 1198904
= 1198904) No
realization exists in (1 + 1)-dimension(xx) 119873119906(119860
1198861
45 minus1 le 119886 lt 1 119886 = 0) sim (119860
11119886
45 minus1 le 119886 lt 1
119886 = 0) (1198901
= 1198901 1198902
= 1198903 1198903
= 1198902 1198904
= 1198904) No
realization exists in (1 + 1)-dimension(xxi) 119873119906(119860
11
45) sim (119860
119886119887
45 119886 = 119887 = 119888 = 1) (119890
1= 1198902 1198902= 1198903
1198903= 1198901 1198904= 1198904)
119873119906(11986011
45) sim 119877(119860
119886119887
45 10 119886 = 119887 = 119888 = 1) (119905 = 119910
119909 = 119909)(xxii) 119873119906(119860
119886119887
46 119886 = 0 119887 ge 0) sim (119860
119886119887
46 119886 gt 0) (119890
1= 1198901
1198902= 1198903 1198903= minus1198902 1198904= 1198904)
119873119906(119860119886119887
46 119886 = 0 119887 ge 0) sim 119877(119860
119886119887
46 6 119886 gt 0) (119905 =
119910(1 + 1199092)minus12
119890(119886minus119887)tanminus1119909
119909 = tanminus1119909)
Journal of Applied Mathematics 3
Table 1
Lie algebra 119873 Realizations (generators)41198601
11 120597119905 119909120597119905 119896(119909)120597
119905 ℎ(119909)120597
119905
211986021
5 120597119905 119905120597119905 120597119909 119909120597119909
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
11986032
oplus 1198601
9 120597119905 119909120597119905 119905120597119905minus120597119909 119890minus119909
120597119905
119860119886
34oplus 1198601 |119886| le 1 119886 = 0 1 9 120597
119905 119909120597119905 119905120597119905+ (1 minus 119886)119909120597
119909 |119909|1(1minus119886)
120597119905
119860119887
35oplus 1198601 119887 ge 0 8 120597
119905 119909120597119905 (119887 minus 119909)119905120597
119905minus (1 + 119909
2)120597119909 radic1 + 119909
2119890minus119887 arctan 119909
120597119905
Sl(2 R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
9 120597119905 119905120597119905 1199052120597119905 120597119909
11986041
8 120597119905 119909120597119905 (12) 119909
2120597119905 minus120597119909
119860119887
42 119887 = 0 8 120597
119905 119909120597119905 (1 (1 minus 119887)) 119909 ln |119909| 120597
119905 119887119905120597
119905+ (119887 minus 1)119909120597
119909 119887 = 1
11986043
8 120597119905 119909120597119905 minus119909 ln |119909| 120597
119905 119905120597119905+ 119909120597119909
11986044
7 120597119905 119909120597119905 (12) 119909
2120597119905 119905120597119905minus120597119909
119860119886 119887 119888
45 minus1 le 119886 lt 119887 lt 119888 = 1 119886119887119888 = 0
7 120597119905 119890(119886minus119887)119909
120597119905 119890(119886minus1)119909
120597119905 119886119905120597
119905+120597119909 119887 gt 0 if 119886 = minus1
10 120597119905 119909120597119905 120601(119909)120597
119905 119905120597119905 12060110158401015840(119909) = 0 119886 = 119887 = 119888 = 1
119860119886 119887
46 119886 gt 0 6 120597
119905 119890(119886minus119887)119909 cos 119909120597
119905 minus119890(119886minus119887)119909 sin119909120597
119905 119886119905120597
119905+120597119909
11986047
5 120597119905 119909120597119905 minus120597
119909 (2119905 minus (12) 119909
2)120597119905+ 119909120597119909
119860119887
48 |119887| le 1
5 120597119905 120597119909 119909120597119905 (1 + 119887)119905120597
119905+ 119909120597119909
lowast7 120597119905 119909120597119905 minus120597
119909 (1 + 119887)119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
7 120597119905 119909120597119905 119905120597119905 minus119905119909120597
119905minus (1 + 119909
2)120597119909
(xxiii) 119873119906(11986047
) sim (11986047
)119873119906(119860
47) sim 119877(119860
47 5) (119905 = 119910 + (119909
24)(1 minus 2 log |119909|)
119909 = 119909)
(xxiv) 119873119906(11986048
) sim (119860119887
48 |119887| le 1 119887 = minus1)
119873119906(11986048
) sim 119877(119860119887
48 |119887| le 1 5 119887 = minus1) (119905 = 119910
119909 = 119909)
(xxv) 119873119906(119860119887
49 0 lt |119887| lt 1) sim (119860
119887
48 |119887| le 1 119887 = plusmn 1 0)
119873119906(119860119887
49) sim 119877(119860
119887
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = plusmn 1 0) is missing in [6]
(xxvi) 119873119906(1198601
49) sim (119860
119887
48 119887 = 1)
119873119906(1198601
49) sim 119877(119860
1
48 5) (119905 = 119910 119909 = 119909)
(xxvii) 119873119906(1198600
49) sim (119860
119887
48 119887 = 0)
119873119906(1198600
49) sim 119877(119860
0
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = 0) is missing in [6]
(xxviii) 119873119906(119860410
) sim (119860119886
49 119886 = 0) No realization exists in
(1 + 1)-dimension
(xxix) 119873119906(119860119886
411 119886 gt 0) sim (119860
119886
49 119886 gt 0) No realization
exists in (1 + 1)-dimension
(xxx) 119873119906(119860412
) sim (119860410
)119873119906(119860
412) sim 119877(119860
410 7) (119905 = 119910 119909 = 119909) whereas
119877(119860410
6) is missing in [6]
Remarks for Table 1
(i) 41198601 1 119909 ℎ(119909) and 119896(119909) form a linearly independent
set
Remarks for Tables 1 and 2 In both tables we have
(i) ℎ 119896 and 120601 are arbitrary functions with specifiedconditions mentioned in the corresponding realiza-tions
(ii) 119886 119887 and 119888 are parameters and arbitrary constantswhose range and values are mentioned in each of therealizations
(iii) lowast these are the cases of realizations which aremissingin [6]
Remarks for Table 2
(i) lowast these are the canonical forms of fourth-orderODEswhich are missing in [6] Only these are given herewith their corresponding algebras and realizations
4 Journal of Applied Mathematics
Table 2
Lie algebra 119873 Realizations and equations
211986021
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
sdotsdotsdotsdot
119909=10
minus
153
2
+2
1199092
119891(119909
minus
3119909
2
)
Sl(2R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
sdotsdotsdotsdot
119909= minus2
119909+
1
1199093(
2
2minus 119909)
2
119891(1199092
((22) minus 119909)
32)
119860119887
48 |119887| le 1
lowast7 120597119905 119909120597119905 minus120597119909 (1 + 119887) 119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
sdotsdotsdotsdot
119909=10
minus
153
2
+ (1minus3119887)(1minus119887)
(4minus2119887)(1minus119887)
119891((
4minus
32
5)(
3)
(1minus2119887)(119887minus1)
)
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
sdotsdotsdotsdot
119909=10
(1 + 2)minus
1523
(1 + 2)2+
3
(1 + 2)2119891(
(1 + 2)
2
minus 3)
3 Concluding Remarks
In this contribution we have supplemented the work [6] forthe canonical forms of scalar fourth-order ODEs and haveobtained four new forms as listed in Table 2The integrabilityof these equations has the same route as the others which arediscussed at length in [6]
Acknowledgments
A Fatima gratefully acknowledges the financial supportand scholarship from School of Computational and AppliedMathematics University of the Witwatersrand
References
[1] S Lie ldquoClassification und Integration von gewohnlichen Dif-ferentialgleichungen zwischen x y die eine Gruppe von Trans-formationen gestattenrdquoMathematische Annalen vol 8 no 9 p187 1888
[2] P J Olver Applications of Lie Groups to Differential Equationsvol 107 Springer New York NY USA 2nd edition 1993
[3] A H Kara F M Mahomed and P G L Leach ldquoNoetherequivalence problem for particle Lagrangiansrdquo Journal of Math-ematical Analysis and Applications vol 188 no 3 pp 867ndash8841994
[4] F M Mahomed and P G L Leach ldquoNormal forms for third-order equationsrdquo in Proceedings of the Workshop on FiniteDimensional Integrable Nonlinear Dynamical Systems P G LLeach and W H Steeb Eds p 178 World Scientic Johannes-burg South Africa 1988
[5] N H Ibragimov and M C Nucci ldquoIntegration of thirdorder ordinary differential equations by lies method equationsadmitting three-dimensional lie algebrasrdquo Lie Groups andTheirApplications vol 1 p 4964 1994
[6] T Cerquetelli N Ciccoli and M C Nucci ldquoFour dimensionalLie symmetry algebras and fourth order ordinary differentialequationsrdquo Journal of Nonlinear Mathematical Physics vol 9supplement 2 pp 24ndash35 2002
[7] J Patera and PWinternitz ldquoSubalgebras of real three- and four-dimensional Lie algebrasrdquo Journal of Mathematical Physics vol18 no 7 pp 1449ndash1455 1977
[8] FMMahomed and P G L Leach ldquoLie algebras associated withscalar second-order ordinary differential equationsrdquo Journal ofMathematical Physics vol 30 no 12 pp 2770ndash2777 1989
[9] R O Popovych V M Boyko M O Nesterenko and M WLutfullin ldquoRealizations of real low-dimensional Lie algebrasrdquoJournal of Physics A vol 36 no 26 pp 7337ndash7360 2003
[10] G Bluman and S Kumei ldquoOn invariance properties of the waveequationrdquo Journal of Mathematical Physics vol 28 no 2 pp307ndash318 1987
[11] S P TimoshenkoTheory of Elastic Stability McGraw-Hill NewYork NY USA 2nd edition 1961
[12] A H Bokhari F M Mahomed and F D Zaman ldquoSymmetriesand integrability of a fourth-order Euler-Bernoulli beam equa-tionrdquo Journal of Mathematical Physics vol 51 no 5 Article ID053517 2010
[13] F I Leite P D Lea and T Mariano ldquoSymmetry and integrabil-ity of a fourth-order Emden-Fowler equationrdquo Technical ReportCMCC-UFABC1-13 2012
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2 Journal of Applied Mathematics
the linear wave equation in an inhomogeneous medium (see[10]) they occur prominently as model equations in the formof the static Euler-Bernoulli beam (see eg [11]) and Emden-Fowler equations Such equations have been investigated forsymmetry properties in [12 13]
Firstly we provide a comparison of the results of [9] andthat of [6] related to the realizations of four-dimensional Liealgebras as vector fields in the plane Then we list the newcanonical forms of scalar fourth-order ODEs which possessfour-dimensional algebras
2 Comparison of the Results of [6 9]
We show here that the results on realizations of four-dimensional algebras in the plane given in [6] are a specialcase of the corresponding set of realizations given in [9] Wemake a comparison of the lists of realizations given in [6]and [9] It should be remarked that in general a result ofclassification of realizations may contain errors of two typesnamely
(i) missing of some inequivalent cases and(ii) mutually equivalent cases
In the following comparison some first type of errorsexist in [6] Five cases are missing There are some othercases which can be combined in a compact form and alsosome arbitrary parameters and functions need modificationaccording to the results of [9] related to realizations in theplane Below we keep the notations of both on the left handside the notations of [6] and on right hand side that of [9]However for the final results and further utilization we keepthe notations of [9]
21 Four-Dimensional Algebras We use the nomenclature ofPatera and Winternitz [7] in the naming of the algebras suchas 4119860
1Thuswe do not provide a table of the abstract algebras
of dimension four as this is easily availableHere the 119873119906 refers to the realizations given in the work
[6] and 119877 to that of [9]
(i) 119873119906(41198601) sim (4119860
1) (1198901= 1198902 1198902= 1198903 1198903= 1198901 1198904= 1198904)
119873119906(41198601) sim 119877(4119860
1 11) (119905 = 119910 119909 = 119909)
(ii) 119873119906(1198602oplus21198601) sim (119860
21oplus21198601) (1198901= 1198902 1198902= minus1198901 1198903=
11989031198904= 1198904) No realization exists in (1+1)-dimension
(iii) 119873119906(21198602) sim (2119860
21) (1198901
= 1198902 1198902
= minus1198901 1198903
= 1198904
1198904= minus1198903)
119873119906(21198602) sim 119877(2119860
21 5) (119905 = 119909 119909 = 119910) whereas
119877(211986021
7) is missing in [6](iv) 119873119906(119860
31oplus1198601) sim (119860
31oplus1198601) No realization exists in
(1 + 1)-dimension(v) 119873119906(119860
32oplus 1198601 119891(119909) = 0) sim (119860
32oplus 1198601)
119873119906(11986032
oplus 1198601 119891(119909) = 0) sim 119877(119860
32oplus 1198601 9) (119905 = 119910
119909 = minus119909)
(vi) 119873119906(11986033
oplus1198601) sim (119860
33oplus1198601) No realization exists in
(1 + 1)-dimension
(vii) 119873119906(11986034
oplus 1198601 119891(119909) = 0) sim (119860
119886
34oplus 1198601 119886 = minus1)
119873119906(11986034
oplus 1198601 119891(119909) = 0) sim 119877(119860
119886
34oplus 1198601 9 119886 = minus1)
(119905 = 119910 119909 = 1199092)
(viii) 119873119906(119860119886
35oplus1198601 0 lt |119886| lt 1 119891(119909) = 0) sim (119860
119886
34oplus
1198601 |119886| le 1 119886 = 0 plusmn1)
119873119906(119860119886
35oplus 1198601 0 lt |119886| lt 1 119891(119909) = 0) sim 119877(119860
119886
34oplus
1198601 9) (119905 = 119910 119909 = 119909
1minus119886)
(ix) 119873119906(11986036
oplus 1198601 119891(119909) = 0) sim (119860
119887
35oplus 1198601 119887 = 0)
119873119906(11986036
oplus 1198601 119891(119909) = 0) sim 119877(119860
119887
35oplus 1198601 8 119887 = 0)
(119905 = 119910 119909 = (1199092minus 1)12
)
(x) 119873119906(119860119887
37oplus1198601 119887 gt 0 119891(119909) = 0) sim (119860
119887
35oplus1198601 119887 gt 0)
119873119906(119860119887
37oplus 1198601 119887 gt 0 119891(119909) = 0) sim 119877(119860
119887
35oplus 1198601 8
119887 gt 0) (119905 = 119910 119909 = 119909)
(xi) 119873119906(11986038
oplus 1198601 119891(119909) = 1) sim (Sl(2R) oplus 119860
1) (1198901= 1198901
1198902= 1198902 1198903= minus1198903 1198904= 1198904)
119873119906(11986038
oplus 1198601 119887 gt 0 119891(119909) = 1) sim 119877(Sl(2R) oplus
1198601 9) (119905 = 119910 119909 = 119909) whereas 119877(Sl(2 R) oplus 119860
1 8))
is missing in [6](xii) 119873119906(119860
39oplus 1198601) sim (So(3) oplus 119860
1) No realization exists
in (1 + 1)-dimension(xiii) 119873119906(119860
41 119891(119909) = 0) sim (119860
41)
119873119906(11986041
119891(119909) = 0) sim 119877(11986041
8) (119905 = 119910 119909 = 119909)
(xiv) 119873119906(119860119887
42 119887 = 0 1) sim (119860
119887
42 119887 = 0 1) (119890
1= 1198901 1198902= minus1198902
1198903= minus1198903 1198904= 1198904)
119873119906(119860119887
42) sim 119877(119860
119887
42 8) (119905 = 119890
(119887minus1)119909119910 119909 = 119890
(119887minus1)119909)
(xv) 119873119906(1198601
42) sim (119860
119887
42 119887 = 1) No realization exists in (1 +
1)-dimension(xvi) 119873119906(119860
43 119891(119909) = 0) sim (119860
43)
119873119906(11986043
119891(119909) = 0) sim 119877(11986043
8) (119905 = 119910 119909 = 119909)(xvii) 119873119906(119860
44 119891(119909) = 0) sim (119860
44)
119873119906(11986044
119891(119909) = 0) sim 119877(11986044
7) (119905 = 119910 119909 = 119909)
(xviii) 119873119906(119860119886119887
45 minus1 le 119886 lt 119887 lt 1 119886119887 = 0) sim (119860
119886119887
45 minus1 le
119886 lt 119887 lt 119888 = 1 119886119887119888 = 0) (1198901
= 1198902 1198902
= 1198903 1198903
= 1198901
1198904= 1198904)
119873119906(119860119886119887
45 minus1 le 119886 lt 119887 lt 1 119886119887 = 0) sim 119877(119860
119886119887
45 7 minus1 le
119886 lt 119887 lt 119888 = 1 119886119887119888 = 0 119887 gt 0 if 119886 = minus1) (119905 = 119909119886minus1
119910 +
119909119886 ln(1|119909|) 119909 = ln |119909|)
(xix) (119860119886119886
45 minus1 le 119886 lt 1 119886 = 0) sim (119860
11119886minus1
45 minus1 le 119886 lt 1
119886 = 0) (1198901
= 1198903 1198902
= 1198902 1198903
= 1198901 1198904
= 1198904) No
realization exists in (1 + 1)-dimension(xx) 119873119906(119860
1198861
45 minus1 le 119886 lt 1 119886 = 0) sim (119860
11119886
45 minus1 le 119886 lt 1
119886 = 0) (1198901
= 1198901 1198902
= 1198903 1198903
= 1198902 1198904
= 1198904) No
realization exists in (1 + 1)-dimension(xxi) 119873119906(119860
11
45) sim (119860
119886119887
45 119886 = 119887 = 119888 = 1) (119890
1= 1198902 1198902= 1198903
1198903= 1198901 1198904= 1198904)
119873119906(11986011
45) sim 119877(119860
119886119887
45 10 119886 = 119887 = 119888 = 1) (119905 = 119910
119909 = 119909)(xxii) 119873119906(119860
119886119887
46 119886 = 0 119887 ge 0) sim (119860
119886119887
46 119886 gt 0) (119890
1= 1198901
1198902= 1198903 1198903= minus1198902 1198904= 1198904)
119873119906(119860119886119887
46 119886 = 0 119887 ge 0) sim 119877(119860
119886119887
46 6 119886 gt 0) (119905 =
119910(1 + 1199092)minus12
119890(119886minus119887)tanminus1119909
119909 = tanminus1119909)
Journal of Applied Mathematics 3
Table 1
Lie algebra 119873 Realizations (generators)41198601
11 120597119905 119909120597119905 119896(119909)120597
119905 ℎ(119909)120597
119905
211986021
5 120597119905 119905120597119905 120597119909 119909120597119909
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
11986032
oplus 1198601
9 120597119905 119909120597119905 119905120597119905minus120597119909 119890minus119909
120597119905
119860119886
34oplus 1198601 |119886| le 1 119886 = 0 1 9 120597
119905 119909120597119905 119905120597119905+ (1 minus 119886)119909120597
119909 |119909|1(1minus119886)
120597119905
119860119887
35oplus 1198601 119887 ge 0 8 120597
119905 119909120597119905 (119887 minus 119909)119905120597
119905minus (1 + 119909
2)120597119909 radic1 + 119909
2119890minus119887 arctan 119909
120597119905
Sl(2 R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
9 120597119905 119905120597119905 1199052120597119905 120597119909
11986041
8 120597119905 119909120597119905 (12) 119909
2120597119905 minus120597119909
119860119887
42 119887 = 0 8 120597
119905 119909120597119905 (1 (1 minus 119887)) 119909 ln |119909| 120597
119905 119887119905120597
119905+ (119887 minus 1)119909120597
119909 119887 = 1
11986043
8 120597119905 119909120597119905 minus119909 ln |119909| 120597
119905 119905120597119905+ 119909120597119909
11986044
7 120597119905 119909120597119905 (12) 119909
2120597119905 119905120597119905minus120597119909
119860119886 119887 119888
45 minus1 le 119886 lt 119887 lt 119888 = 1 119886119887119888 = 0
7 120597119905 119890(119886minus119887)119909
120597119905 119890(119886minus1)119909
120597119905 119886119905120597
119905+120597119909 119887 gt 0 if 119886 = minus1
10 120597119905 119909120597119905 120601(119909)120597
119905 119905120597119905 12060110158401015840(119909) = 0 119886 = 119887 = 119888 = 1
119860119886 119887
46 119886 gt 0 6 120597
119905 119890(119886minus119887)119909 cos 119909120597
119905 minus119890(119886minus119887)119909 sin119909120597
119905 119886119905120597
119905+120597119909
11986047
5 120597119905 119909120597119905 minus120597
119909 (2119905 minus (12) 119909
2)120597119905+ 119909120597119909
119860119887
48 |119887| le 1
5 120597119905 120597119909 119909120597119905 (1 + 119887)119905120597
119905+ 119909120597119909
lowast7 120597119905 119909120597119905 minus120597
119909 (1 + 119887)119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
7 120597119905 119909120597119905 119905120597119905 minus119905119909120597
119905minus (1 + 119909
2)120597119909
(xxiii) 119873119906(11986047
) sim (11986047
)119873119906(119860
47) sim 119877(119860
47 5) (119905 = 119910 + (119909
24)(1 minus 2 log |119909|)
119909 = 119909)
(xxiv) 119873119906(11986048
) sim (119860119887
48 |119887| le 1 119887 = minus1)
119873119906(11986048
) sim 119877(119860119887
48 |119887| le 1 5 119887 = minus1) (119905 = 119910
119909 = 119909)
(xxv) 119873119906(119860119887
49 0 lt |119887| lt 1) sim (119860
119887
48 |119887| le 1 119887 = plusmn 1 0)
119873119906(119860119887
49) sim 119877(119860
119887
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = plusmn 1 0) is missing in [6]
(xxvi) 119873119906(1198601
49) sim (119860
119887
48 119887 = 1)
119873119906(1198601
49) sim 119877(119860
1
48 5) (119905 = 119910 119909 = 119909)
(xxvii) 119873119906(1198600
49) sim (119860
119887
48 119887 = 0)
119873119906(1198600
49) sim 119877(119860
0
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = 0) is missing in [6]
(xxviii) 119873119906(119860410
) sim (119860119886
49 119886 = 0) No realization exists in
(1 + 1)-dimension
(xxix) 119873119906(119860119886
411 119886 gt 0) sim (119860
119886
49 119886 gt 0) No realization
exists in (1 + 1)-dimension
(xxx) 119873119906(119860412
) sim (119860410
)119873119906(119860
412) sim 119877(119860
410 7) (119905 = 119910 119909 = 119909) whereas
119877(119860410
6) is missing in [6]
Remarks for Table 1
(i) 41198601 1 119909 ℎ(119909) and 119896(119909) form a linearly independent
set
Remarks for Tables 1 and 2 In both tables we have
(i) ℎ 119896 and 120601 are arbitrary functions with specifiedconditions mentioned in the corresponding realiza-tions
(ii) 119886 119887 and 119888 are parameters and arbitrary constantswhose range and values are mentioned in each of therealizations
(iii) lowast these are the cases of realizations which aremissingin [6]
Remarks for Table 2
(i) lowast these are the canonical forms of fourth-orderODEswhich are missing in [6] Only these are given herewith their corresponding algebras and realizations
4 Journal of Applied Mathematics
Table 2
Lie algebra 119873 Realizations and equations
211986021
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
sdotsdotsdotsdot
119909=10
minus
153
2
+2
1199092
119891(119909
minus
3119909
2
)
Sl(2R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
sdotsdotsdotsdot
119909= minus2
119909+
1
1199093(
2
2minus 119909)
2
119891(1199092
((22) minus 119909)
32)
119860119887
48 |119887| le 1
lowast7 120597119905 119909120597119905 minus120597119909 (1 + 119887) 119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
sdotsdotsdotsdot
119909=10
minus
153
2
+ (1minus3119887)(1minus119887)
(4minus2119887)(1minus119887)
119891((
4minus
32
5)(
3)
(1minus2119887)(119887minus1)
)
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
sdotsdotsdotsdot
119909=10
(1 + 2)minus
1523
(1 + 2)2+
3
(1 + 2)2119891(
(1 + 2)
2
minus 3)
3 Concluding Remarks
In this contribution we have supplemented the work [6] forthe canonical forms of scalar fourth-order ODEs and haveobtained four new forms as listed in Table 2The integrabilityof these equations has the same route as the others which arediscussed at length in [6]
Acknowledgments
A Fatima gratefully acknowledges the financial supportand scholarship from School of Computational and AppliedMathematics University of the Witwatersrand
References
[1] S Lie ldquoClassification und Integration von gewohnlichen Dif-ferentialgleichungen zwischen x y die eine Gruppe von Trans-formationen gestattenrdquoMathematische Annalen vol 8 no 9 p187 1888
[2] P J Olver Applications of Lie Groups to Differential Equationsvol 107 Springer New York NY USA 2nd edition 1993
[3] A H Kara F M Mahomed and P G L Leach ldquoNoetherequivalence problem for particle Lagrangiansrdquo Journal of Math-ematical Analysis and Applications vol 188 no 3 pp 867ndash8841994
[4] F M Mahomed and P G L Leach ldquoNormal forms for third-order equationsrdquo in Proceedings of the Workshop on FiniteDimensional Integrable Nonlinear Dynamical Systems P G LLeach and W H Steeb Eds p 178 World Scientic Johannes-burg South Africa 1988
[5] N H Ibragimov and M C Nucci ldquoIntegration of thirdorder ordinary differential equations by lies method equationsadmitting three-dimensional lie algebrasrdquo Lie Groups andTheirApplications vol 1 p 4964 1994
[6] T Cerquetelli N Ciccoli and M C Nucci ldquoFour dimensionalLie symmetry algebras and fourth order ordinary differentialequationsrdquo Journal of Nonlinear Mathematical Physics vol 9supplement 2 pp 24ndash35 2002
[7] J Patera and PWinternitz ldquoSubalgebras of real three- and four-dimensional Lie algebrasrdquo Journal of Mathematical Physics vol18 no 7 pp 1449ndash1455 1977
[8] FMMahomed and P G L Leach ldquoLie algebras associated withscalar second-order ordinary differential equationsrdquo Journal ofMathematical Physics vol 30 no 12 pp 2770ndash2777 1989
[9] R O Popovych V M Boyko M O Nesterenko and M WLutfullin ldquoRealizations of real low-dimensional Lie algebrasrdquoJournal of Physics A vol 36 no 26 pp 7337ndash7360 2003
[10] G Bluman and S Kumei ldquoOn invariance properties of the waveequationrdquo Journal of Mathematical Physics vol 28 no 2 pp307ndash318 1987
[11] S P TimoshenkoTheory of Elastic Stability McGraw-Hill NewYork NY USA 2nd edition 1961
[12] A H Bokhari F M Mahomed and F D Zaman ldquoSymmetriesand integrability of a fourth-order Euler-Bernoulli beam equa-tionrdquo Journal of Mathematical Physics vol 51 no 5 Article ID053517 2010
[13] F I Leite P D Lea and T Mariano ldquoSymmetry and integrabil-ity of a fourth-order Emden-Fowler equationrdquo Technical ReportCMCC-UFABC1-13 2012
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Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Journal of Applied Mathematics 3
Table 1
Lie algebra 119873 Realizations (generators)41198601
11 120597119905 119909120597119905 119896(119909)120597
119905 ℎ(119909)120597
119905
211986021
5 120597119905 119905120597119905 120597119909 119909120597119909
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
11986032
oplus 1198601
9 120597119905 119909120597119905 119905120597119905minus120597119909 119890minus119909
120597119905
119860119886
34oplus 1198601 |119886| le 1 119886 = 0 1 9 120597
119905 119909120597119905 119905120597119905+ (1 minus 119886)119909120597
119909 |119909|1(1minus119886)
120597119905
119860119887
35oplus 1198601 119887 ge 0 8 120597
119905 119909120597119905 (119887 minus 119909)119905120597
119905minus (1 + 119909
2)120597119909 radic1 + 119909
2119890minus119887 arctan 119909
120597119905
Sl(2 R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
9 120597119905 119905120597119905 1199052120597119905 120597119909
11986041
8 120597119905 119909120597119905 (12) 119909
2120597119905 minus120597119909
119860119887
42 119887 = 0 8 120597
119905 119909120597119905 (1 (1 minus 119887)) 119909 ln |119909| 120597
119905 119887119905120597
119905+ (119887 minus 1)119909120597
119909 119887 = 1
11986043
8 120597119905 119909120597119905 minus119909 ln |119909| 120597
119905 119905120597119905+ 119909120597119909
11986044
7 120597119905 119909120597119905 (12) 119909
2120597119905 119905120597119905minus120597119909
119860119886 119887 119888
45 minus1 le 119886 lt 119887 lt 119888 = 1 119886119887119888 = 0
7 120597119905 119890(119886minus119887)119909
120597119905 119890(119886minus1)119909
120597119905 119886119905120597
119905+120597119909 119887 gt 0 if 119886 = minus1
10 120597119905 119909120597119905 120601(119909)120597
119905 119905120597119905 12060110158401015840(119909) = 0 119886 = 119887 = 119888 = 1
119860119886 119887
46 119886 gt 0 6 120597
119905 119890(119886minus119887)119909 cos 119909120597
119905 minus119890(119886minus119887)119909 sin119909120597
119905 119886119905120597
119905+120597119909
11986047
5 120597119905 119909120597119905 minus120597
119909 (2119905 minus (12) 119909
2)120597119905+ 119909120597119909
119860119887
48 |119887| le 1
5 120597119905 120597119909 119909120597119905 (1 + 119887)119905120597
119905+ 119909120597119909
lowast7 120597119905 119909120597119905 minus120597
119909 (1 + 119887)119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
7 120597119905 119909120597119905 119905120597119905 minus119905119909120597
119905minus (1 + 119909
2)120597119909
(xxiii) 119873119906(11986047
) sim (11986047
)119873119906(119860
47) sim 119877(119860
47 5) (119905 = 119910 + (119909
24)(1 minus 2 log |119909|)
119909 = 119909)
(xxiv) 119873119906(11986048
) sim (119860119887
48 |119887| le 1 119887 = minus1)
119873119906(11986048
) sim 119877(119860119887
48 |119887| le 1 5 119887 = minus1) (119905 = 119910
119909 = 119909)
(xxv) 119873119906(119860119887
49 0 lt |119887| lt 1) sim (119860
119887
48 |119887| le 1 119887 = plusmn 1 0)
119873119906(119860119887
49) sim 119877(119860
119887
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = plusmn 1 0) is missing in [6]
(xxvi) 119873119906(1198601
49) sim (119860
119887
48 119887 = 1)
119873119906(1198601
49) sim 119877(119860
1
48 5) (119905 = 119910 119909 = 119909)
(xxvii) 119873119906(1198600
49) sim (119860
119887
48 119887 = 0)
119873119906(1198600
49) sim 119877(119860
0
48 5) (119905 = 119910 119909 = 119909) whereas 119877
(119860119887
48 7 119887 = 0) is missing in [6]
(xxviii) 119873119906(119860410
) sim (119860119886
49 119886 = 0) No realization exists in
(1 + 1)-dimension
(xxix) 119873119906(119860119886
411 119886 gt 0) sim (119860
119886
49 119886 gt 0) No realization
exists in (1 + 1)-dimension
(xxx) 119873119906(119860412
) sim (119860410
)119873119906(119860
412) sim 119877(119860
410 7) (119905 = 119910 119909 = 119909) whereas
119877(119860410
6) is missing in [6]
Remarks for Table 1
(i) 41198601 1 119909 ℎ(119909) and 119896(119909) form a linearly independent
set
Remarks for Tables 1 and 2 In both tables we have
(i) ℎ 119896 and 120601 are arbitrary functions with specifiedconditions mentioned in the corresponding realiza-tions
(ii) 119886 119887 and 119888 are parameters and arbitrary constantswhose range and values are mentioned in each of therealizations
(iii) lowast these are the cases of realizations which aremissingin [6]
Remarks for Table 2
(i) lowast these are the canonical forms of fourth-orderODEswhich are missing in [6] Only these are given herewith their corresponding algebras and realizations
4 Journal of Applied Mathematics
Table 2
Lie algebra 119873 Realizations and equations
211986021
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
sdotsdotsdotsdot
119909=10
minus
153
2
+2
1199092
119891(119909
minus
3119909
2
)
Sl(2R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
sdotsdotsdotsdot
119909= minus2
119909+
1
1199093(
2
2minus 119909)
2
119891(1199092
((22) minus 119909)
32)
119860119887
48 |119887| le 1
lowast7 120597119905 119909120597119905 minus120597119909 (1 + 119887) 119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
sdotsdotsdotsdot
119909=10
minus
153
2
+ (1minus3119887)(1minus119887)
(4minus2119887)(1minus119887)
119891((
4minus
32
5)(
3)
(1minus2119887)(119887minus1)
)
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
sdotsdotsdotsdot
119909=10
(1 + 2)minus
1523
(1 + 2)2+
3
(1 + 2)2119891(
(1 + 2)
2
minus 3)
3 Concluding Remarks
In this contribution we have supplemented the work [6] forthe canonical forms of scalar fourth-order ODEs and haveobtained four new forms as listed in Table 2The integrabilityof these equations has the same route as the others which arediscussed at length in [6]
Acknowledgments
A Fatima gratefully acknowledges the financial supportand scholarship from School of Computational and AppliedMathematics University of the Witwatersrand
References
[1] S Lie ldquoClassification und Integration von gewohnlichen Dif-ferentialgleichungen zwischen x y die eine Gruppe von Trans-formationen gestattenrdquoMathematische Annalen vol 8 no 9 p187 1888
[2] P J Olver Applications of Lie Groups to Differential Equationsvol 107 Springer New York NY USA 2nd edition 1993
[3] A H Kara F M Mahomed and P G L Leach ldquoNoetherequivalence problem for particle Lagrangiansrdquo Journal of Math-ematical Analysis and Applications vol 188 no 3 pp 867ndash8841994
[4] F M Mahomed and P G L Leach ldquoNormal forms for third-order equationsrdquo in Proceedings of the Workshop on FiniteDimensional Integrable Nonlinear Dynamical Systems P G LLeach and W H Steeb Eds p 178 World Scientic Johannes-burg South Africa 1988
[5] N H Ibragimov and M C Nucci ldquoIntegration of thirdorder ordinary differential equations by lies method equationsadmitting three-dimensional lie algebrasrdquo Lie Groups andTheirApplications vol 1 p 4964 1994
[6] T Cerquetelli N Ciccoli and M C Nucci ldquoFour dimensionalLie symmetry algebras and fourth order ordinary differentialequationsrdquo Journal of Nonlinear Mathematical Physics vol 9supplement 2 pp 24ndash35 2002
[7] J Patera and PWinternitz ldquoSubalgebras of real three- and four-dimensional Lie algebrasrdquo Journal of Mathematical Physics vol18 no 7 pp 1449ndash1455 1977
[8] FMMahomed and P G L Leach ldquoLie algebras associated withscalar second-order ordinary differential equationsrdquo Journal ofMathematical Physics vol 30 no 12 pp 2770ndash2777 1989
[9] R O Popovych V M Boyko M O Nesterenko and M WLutfullin ldquoRealizations of real low-dimensional Lie algebrasrdquoJournal of Physics A vol 36 no 26 pp 7337ndash7360 2003
[10] G Bluman and S Kumei ldquoOn invariance properties of the waveequationrdquo Journal of Mathematical Physics vol 28 no 2 pp307ndash318 1987
[11] S P TimoshenkoTheory of Elastic Stability McGraw-Hill NewYork NY USA 2nd edition 1961
[12] A H Bokhari F M Mahomed and F D Zaman ldquoSymmetriesand integrability of a fourth-order Euler-Bernoulli beam equa-tionrdquo Journal of Mathematical Physics vol 51 no 5 Article ID053517 2010
[13] F I Leite P D Lea and T Mariano ldquoSymmetry and integrabil-ity of a fourth-order Emden-Fowler equationrdquo Technical ReportCMCC-UFABC1-13 2012
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
4 Journal of Applied Mathematics
Table 2
Lie algebra 119873 Realizations and equations
211986021
lowast7 120597119905 119905120597119905+ 119909120597119909 119909120597119905 minus119909120597
119909
sdotsdotsdotsdot
119909=10
minus
153
2
+2
1199092
119891(119909
minus
3119909
2
)
Sl(2R) oplus 1198601
lowast8 120597119905 119905120597119905+ 119909120597119909 1199052120597119905+ 2119905119909120597
119909 119909120597119909
sdotsdotsdotsdot
119909= minus2
119909+
1
1199093(
2
2minus 119909)
2
119891(1199092
((22) minus 119909)
32)
119860119887
48 |119887| le 1
lowast7 120597119905 119909120597119905 minus120597119909 (1 + 119887) 119905120597
119905+ 119887119909120597
119909 119887 = plusmn 1
sdotsdotsdotsdot
119909=10
minus
153
2
+ (1minus3119887)(1minus119887)
(4minus2119887)(1minus119887)
119891((
4minus
32
5)(
3)
(1minus2119887)(119887minus1)
)
119860410
lowast6 120597119905 120597119909 119905120597119905+ 119909120597119909 119909120597119905minus 119905120597119909
sdotsdotsdotsdot
119909=10
(1 + 2)minus
1523
(1 + 2)2+
3
(1 + 2)2119891(
(1 + 2)
2
minus 3)
3 Concluding Remarks
In this contribution we have supplemented the work [6] forthe canonical forms of scalar fourth-order ODEs and haveobtained four new forms as listed in Table 2The integrabilityof these equations has the same route as the others which arediscussed at length in [6]
Acknowledgments
A Fatima gratefully acknowledges the financial supportand scholarship from School of Computational and AppliedMathematics University of the Witwatersrand
References
[1] S Lie ldquoClassification und Integration von gewohnlichen Dif-ferentialgleichungen zwischen x y die eine Gruppe von Trans-formationen gestattenrdquoMathematische Annalen vol 8 no 9 p187 1888
[2] P J Olver Applications of Lie Groups to Differential Equationsvol 107 Springer New York NY USA 2nd edition 1993
[3] A H Kara F M Mahomed and P G L Leach ldquoNoetherequivalence problem for particle Lagrangiansrdquo Journal of Math-ematical Analysis and Applications vol 188 no 3 pp 867ndash8841994
[4] F M Mahomed and P G L Leach ldquoNormal forms for third-order equationsrdquo in Proceedings of the Workshop on FiniteDimensional Integrable Nonlinear Dynamical Systems P G LLeach and W H Steeb Eds p 178 World Scientic Johannes-burg South Africa 1988
[5] N H Ibragimov and M C Nucci ldquoIntegration of thirdorder ordinary differential equations by lies method equationsadmitting three-dimensional lie algebrasrdquo Lie Groups andTheirApplications vol 1 p 4964 1994
[6] T Cerquetelli N Ciccoli and M C Nucci ldquoFour dimensionalLie symmetry algebras and fourth order ordinary differentialequationsrdquo Journal of Nonlinear Mathematical Physics vol 9supplement 2 pp 24ndash35 2002
[7] J Patera and PWinternitz ldquoSubalgebras of real three- and four-dimensional Lie algebrasrdquo Journal of Mathematical Physics vol18 no 7 pp 1449ndash1455 1977
[8] FMMahomed and P G L Leach ldquoLie algebras associated withscalar second-order ordinary differential equationsrdquo Journal ofMathematical Physics vol 30 no 12 pp 2770ndash2777 1989
[9] R O Popovych V M Boyko M O Nesterenko and M WLutfullin ldquoRealizations of real low-dimensional Lie algebrasrdquoJournal of Physics A vol 36 no 26 pp 7337ndash7360 2003
[10] G Bluman and S Kumei ldquoOn invariance properties of the waveequationrdquo Journal of Mathematical Physics vol 28 no 2 pp307ndash318 1987
[11] S P TimoshenkoTheory of Elastic Stability McGraw-Hill NewYork NY USA 2nd edition 1961
[12] A H Bokhari F M Mahomed and F D Zaman ldquoSymmetriesand integrability of a fourth-order Euler-Bernoulli beam equa-tionrdquo Journal of Mathematical Physics vol 51 no 5 Article ID053517 2010
[13] F I Leite P D Lea and T Mariano ldquoSymmetry and integrabil-ity of a fourth-order Emden-Fowler equationrdquo Technical ReportCMCC-UFABC1-13 2012
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of