13 papers
Consistency of Generalised Probabilistic Theories is Undecidable
Serge Massar
Generalised Probabilistic Theories (GPTs) provide a unifying framework encompassing classical theories, quantum theories, as well as hypothetical alternatives. We investigate both…
How the Change in Horizon Area Drives Black Hole Evaporation
S. Massar, R. Parentani
We rephrase the derivation of black hole radiation so as to take into account, at the level of transition amplitudes, the change of the geometry induced by the emission process. Th…
Unitary and non-unitary evolution in quantum cosmology
S. Massar, R. Parentani
We analyse when and why unitarity violations might occur in quantum cosmology restricted to minisuperspace. To this end we discuss in detail backscattering transitions between expa…
Interacting Charged Particles in an Electric Field and the Unruh Effect
Cl. Gabriel, Ph. Spindel, S. Massar +1
We compute the transition amplitudes between charged particles of mass and accelerated by a constant electric field and interacting by the exchange of quanta of a third fie…
Particle creation and non-adiabatic transitions in quantum cosmology
S. Massar, R. Parentani
The aim of this paper is to compute transitions amplitudes in quantum cosmology, and in particular pair creation amplitudes and radiative transitions. To this end, we apply a doubl…
Gravitational Instanton for Black Hole Radiation
S. Massar, R. Parentani
Hawking radiation is derived from the existence of a euclidean instanton which lives in the euclidean black hole geometry. Upon taking into account the gravitational field of the i…