TY - JOUR

T1 - On particle creation in the flat FRW chart of de Sitter spacetime

AU - Haro, Jaume

AU - Elizalde, Emilio

PY - 2008/9/19

Y1 - 2008/9/19

N2 - The conditions of the Gibbons-Hawking effect, i.e., particle production in the Friedmann-Robertson-Walker chart of the de Sitter spacetime, are revisited. For a theory with a massive scalar and a fermionic field it is shown that, if one considers the Bunch-Davies vacuum state at early times, then only in the case that the condition mc2/H ≫ 1 is fulfilled can one assure that a thermal spectrum of radiation at temperature T = H/2πkB, where kB is the Boltzmann constant, will be obtained at late times. It is pointed out that this important proviso (which is nothing else than the adiabatic condition, as we shall see), is missing in several derivations of this effect in the literature, where the thermal spectrum was obtained without imposing any restriction on the relation between the mass of the field, m and the Hubble constant, H. © 2008 IOP Publishing Ltd.

AB - The conditions of the Gibbons-Hawking effect, i.e., particle production in the Friedmann-Robertson-Walker chart of the de Sitter spacetime, are revisited. For a theory with a massive scalar and a fermionic field it is shown that, if one considers the Bunch-Davies vacuum state at early times, then only in the case that the condition mc2/H ≫ 1 is fulfilled can one assure that a thermal spectrum of radiation at temperature T = H/2πkB, where kB is the Boltzmann constant, will be obtained at late times. It is pointed out that this important proviso (which is nothing else than the adiabatic condition, as we shall see), is missing in several derivations of this effect in the literature, where the thermal spectrum was obtained without imposing any restriction on the relation between the mass of the field, m and the Hubble constant, H. © 2008 IOP Publishing Ltd.

U2 - 10.1088/1751-8113/41/37/372003

DO - 10.1088/1751-8113/41/37/372003

M3 - Article

VL - 41

JO - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

SN - 1751-8113

IS - 37

M1 - 372003

ER -