minji-verse(?) coskasi group workshop 2014 at sobaek observatory(11.11~12) oh, minji
TRANSCRIPT
Contents
• What I did (or tried)?– Constraints on distances and growth factors using BOSS
DR11– Distinguishing neutrino’s mass hierarchy (NH or IH)
• On-going work– Constraints on using BOSS DR??– Simulation for testing iPT (Takahiko Matsubara, 2014)– Simulation for DESI
• What I (must, plan to, want to) do?– Study theory on robust way?– Testing GR on cosmic scales from scratch to the end– Simulation on various purpose– Graduation
m
8th UST-KASI workshop 4
Redshift Space Distortion(RSD)
• Improvement in 2D Power spectrum in redshift space– Kaiser(1987)
– Scoccimarro(2004)
– Taruya, Nishimichi, and Saito (Improved)(2010) )( ),(),()()(2)( ),(
~ 42p
FoGTNS kGkBkAkPkPkPkP
)()(2)(),( 42 kPkPkPkP linlinlinKaiser
)( )()(2)( ),(~ 42
pFoG
oscoccimarr kGkPkPkPkP
On-going workConvergence test on Simulation
• Some basics in simulation
i j ij
ji
r
mmG
2
)( ijrwhere
On-going workConvergence test on Simulation
• Some basics in simulation
i j ij
ji
r
mmG
2
)( ijrwhere
N-body method
TreePM (= Tree + PM): This model splits force into long range
force and short range force (Criteria, rs )
- For short range force, Tree code- For long range force, PM code
N-body method
Tree code (Barnes & Hut 1986)
2. Calculating force on a bodyCAC (= Cell Acceptance Criterion, )
- d: the size of the node under consideration
- r: the distance between the body and the node's center-of-mass.
- if , then treat the particles in that cell as a single entity for force calculation
c
c
N-body method
Tree code (Barnes & Hut 1986)2. Calculating force on a body• Terminology– Internal node– External node– Root node– Parents node/ daughter(children) node
– Each internal node has its own informa-tion about c.o.m. and the total mass of all its children body
On-going workSimulation for DESI
• DESI (Dark Energy Spectroscopic Instrument, 2018) The Dark Energy Spectroscopic Instrument (DESI) will measure the effect of dark energy on the expansion of the universe. It will obtain optical spectra for tens of millions of galaxies and quasars, con-structing a 3-dimensional map spanning the nearby universe to 10 billion light years.
DESI will be conducted on the Mayall 4-meter telescope at Kitt Peak National Observatory starting in 2018. DESI is supported by the De-partment of Energy Office of Science to perform this Stage IV dark energy measurement using baryon acoustic oscillations and other techniques that rely on spectroscopic measurements.
Cosmology group at KASI plans to take part in DESI as an associated member institute. We provide an apportunity for young researchers to meet challenges for next decades.
What I (must, plan to, want to) do?
Simulation on various purpose• After N-body (collisionless) simulation
using only Dark Matter particles,
• Simulation for Jeeseon’s work (Cos-mology using Clusters) – Smoothed Particle Hydrodynamics with
high resolution
• Simulation for Yi’s work (?)