Probing Non-Thermal Gravitinos Through Large-Scale Structure Observations

Abstract

We investigate the effects of non-thermally produced dark matter on large-scale structure formation, focusing on the gravitino dark matter. Our analysis shows that large-scale structure measurements from the SDSS LRG data offer a promising approach to probing non-thermally produced gravitinos. Specifically, if gravitinos resulting from neutralino decay constitute a fraction $F_{\text{dec}}=0.35(0.1)$ of the dark matter component, the data exclude bino-like neutralino with a mass $m_{{\chi }_1^0}\lesssim 25(11)\text{ GeV}$ at $95\%\text{ C.L.}$. Furthermore, this constraint appears to be largely independent of the gravitino mass.

Comments: 7 pages, 3 figures, PRD version