Environmental CPT Violation in an Expanding Universe in String Theory

TY - JOUR

T1 - Environmental CPT Violation in an Expanding Universe in String Theory

AU - Ellis, John

AU - E. Mavromatos, Nick

AU - Sarkar, Sarben

N1 - 8 pages, some clarifying remarks and references added,no effects on conclusions

PY - 2013/10/1

Y1 - 2013/10/1

N2 - We consider a model of an expanding Universe in string theory that yields `environmental' CPT violation for fermions, in the sense of different dispersion relations for fermions and antifermions. These are induced by a cosmological background with constant torsion provided by the Kalb-Ramond antisymmetric tensor field (axion) of the string gravitational multiplet. This effect induces different densities of neutrinos and antineutrinos while in chemical equilibrium, offering new scenarios for leptogenesis and baryogenesis even in the absence of CP violation.

AB - We consider a model of an expanding Universe in string theory that yields `environmental' CPT violation for fermions, in the sense of different dispersion relations for fermions and antifermions. These are induced by a cosmological background with constant torsion provided by the Kalb-Ramond antisymmetric tensor field (axion) of the string gravitational multiplet. This effect induces different densities of neutrinos and antineutrinos while in chemical equilibrium, offering new scenarios for leptogenesis and baryogenesis even in the absence of CP violation.

KW - gr-qc

KW - hep-ph

KW - hep-th

U2 - 10.1016/j.physletb.2013.07.016

DO - 10.1016/j.physletb.2013.07.016

M3 - Article

SN - 0370-2693

VL - 725

SP - 407

EP - 411

JO - Physics Letters B

JF - Physics Letters B

IS - 4-5

ER -