Stars and Fundamental Physics

Abstract

Abstract. Stars are powerful sources for weakly interacting particles that are produced by nuclear or plasma processes in their hot interior. These fluxes can be used for direct measurements (e.g. solar or supernova neutrinos) or the back-reaction on the star can be used to derive limits on new particles. We discuss two examples of current interest, the search for solar axions by the CAST experiment at CERN and stellar-evolution limits on the size of putative large extra dimensions.

Equilibrium properties of self-interacting neutrinos in the quasi-particle approach

“…We prove that, under the quasi-particle approximation, these correlation functions can be expressed as products of Wigner functions. As we show, the results obtained using these techniques agree with previous calculations [12,13,14,15]. This paper is organized as follows.…”

Photon splitting in an external magnetic field

“…Nowadays, it is generally recognized that astrophysical objects and processes inside them give us unique possibilities [1] for investigations of particle properties under extreme conditions of a high density and/or temperature of matter, and also of a strong magnetic field. A concept of the astrophysically strong magnetic field has been changed in the recent years and now the field is considered as the strong one if it is much greater than the known Schwinger value, B ≫ B e , B e = m 2 e /e ≃ 4.41 · 10 13 G. Possible mechanisms are now discussed of a generation of such strong fields (B ∼ 10 15 − 10 17 G) in astrophysical cataclysms like a supernova explosion or a coalescence of neutron stars [2,3], and in the early Universe [4].…”

“…Let us note that plasma influences the photon properties similarly. The process γ → νν in plasma is well studied and has an importance in astrophysics as one of the main sources of stellar cooling (see a detailed review in the book [1]). …”

A simple explanation of the PVLAS anomaly in spontaneously broken mirror models

“…It is generally argued that the astrophysical limits on epsilon are very stringent, ǫ < ∼ 10 −14 , arising from energy loss considerations in stars [9,10]. Interestingly though, the published limits apply only in the millicharged mass region above about 1 eV (see e.g.…”

“…Typically, exotic particles shouldn't transport energy faster than energy transport from ordinary photons [9]. The relevant equation governing the radiative energy transport is:…”