Constraints on gravitino decay and the scale of inflation using CMB spectral distortions
Abstract
If local supersymmetry is the correct extension of the standard model of particle physics, then following inflation the early Universe would have been populated by gravitinos produced from scatterings in the hot plasma during reheating. Their abundance is directly related to the magnitude of the reheating temperature. The gravitino lifetime is fixed as a function of its mass, and for gravitinos with lifetimes longer than the age of the Universe at redshift z ≃2 ×1 0^{6} (or roughly 6 ×1 0^{6} s ), decay products can produce spectral distortion of the cosmic microwave background. Currently available COBE/FIRAS limits on spectral distortion can, in certain cases, already be competitive with respect to cosmological constraints from primordial nucleosynthesis for some gravitino decay scenarios. We show how the sensitivity limits on μ and y distortions that can be reached with current technology will improve constraints and possibly rule out a significant portion of the parameter space for gravitino masses and inflation reheating temperatures.
 Publication:

Physical Review D
 Pub Date:
 July 2016
 DOI:
 10.1103/PhysRevD.94.023518
 arXiv:
 arXiv:1512.09212
 Bibcode:
 2016PhRvD..94b3518D
 Keywords:

 High Energy Physics  Phenomenology;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 submitted to Phys. Rev D., 8 pages, 4 figs (1 new figure added, references updated)