White dwarfs as a source of constraints on exotic physics

Abstract

In this paper we briefly review main ideas underlying the constraints on exotic physics coming from Astrophysics already used by the others. Next we present a new bound coming from the White Dwarf cooling. Such stringent bound is possible due to accurate measurements offered by astroseismology. Specifically we consider the G117-B15A pulsating white dwarf (ZZ Ceti star) for which the speed of the period increase has been accurately measured for its fundamental oscillation mode. It has been claimed that this mode detected in G117-B15A is perhaps the most stable oscillation ever recorded in the optical band. Then we review our result concerning the bounds on compactification scale in the theory with large extra dimensions according to Arkani-Hamed, Dimopoulos and Dvali. Because an additional channel of energy loss (Kaluza-Klein gravitons) would speed up the cooling rate, one is able to use the aforementioned stability to derive a bound on compactification scale. We find the lower bound on compactification scale to be Ms > 14.3 TeV/c2 which is more stringent than solar or red-giant bounds, as well as the bound coming from LEP. In final section we point out that pulsating hot “pre-White Dwarf” PG 1159-035 (GW Virginis) whose oscillation period increases at the rate of the order of magnitude larger than predicted could be a promising object for further investigations.