Finite-temperature supersymmetry: the Wess–Zumino model

Abstract

We investigate the breakdown of supersymmetry at finite temperature. While it has been proven that temperature always breaks supersymmetry, the nature of this breaking is less clear. On the one hand, a study of the Ward-Takahashi identities suggests a spontaneous breakdown of supersymmetry without the existence of a Goldstino, while on the other hand it has been shown that in any supersymmetric plasma there should exist a massless fermionic collective excitation, the phonino. Aim of this work is to unify these two approaches. For the Wess-Zumino model, it is shown that the phonino exists and contributes to the supersymmetric Ward-Takahashi identities in the right way displaying that supersymmetry is broken spontaneously with the phonino as the Goldstone fermion.

Cosmology with orthogonal nilpotent superfields

“…We see that the transverse modes ψ T have canonical kinetic terms, but the spatial part of the kinetic terms for the longitudinal modes θ are modified by the matrixÂ. As recently emphasized in [7], these modifications to the kinetic structure are known as the "slow gravitino" [50][51][52][53][54] and are required to consistently embed supersymmetry in a (cosmological) fluid background.…”

Vacuum fluctuations in a supersymmetric model in FRW spacetime

“…Since the global geometry is nonflat, the lack of Poincaré symmetry will lift the Fermi-Bose degeneracy and the energy density of vacuum fluctuations will be nonzero. This type of ''soft'' supersymmetry breaking is similar to the supersymmetry breaking at finite temperature where the Fermi-Bose degeneracy is lifted by quantum statistics ( [9] and references therein).…”

The slow gravitino

“…The longitudinal mode inherits its dispersion relation from that of the fluid goldstino [7][8][9][10][11][12] and is nonrelativistic. The transverse mode has the same mass but has a relativistic dispersion relation [6].…”