CMB constraints on Lorentz violation in the neutrino sector

Zong-Kuan Guo (ITP, CAS)

Weihai

August 13, 2012

outline

• motivations• deformed dispersion relation• Boltzmann equation• cosmological constraints• remarks

This talk is based onZKG, Q-G Huang, R-G Cai, Y-Z Zhang, PRD in press [arXiv:1206.5588]

motivations

neutrino oscillations neutrinos influence the CMB (massive or massless) neutrinos influence the LSS

the deformed dispersion relation

the scalar perturbations of the FLRW metric in the synchronous gauge

the action in the first-order formalism

the Lagrangian in the synchronous gauge

the number density, energy density and pressure

the perturbed energy density, pressure, energy flux and shear stress

the Boltzmann equation

the initial conditions

cosmological constraints

remarks

Compared to particle physics experiments, cosmological observations yield much weaker constraints on the Lorentz-violation parameter in the neutrino sector.

We neglects neutrino oscillations, possible species dependence, anisotropies associated with violations of rotation symmetry, and CPT violation.

Thanks!