36344802
Quantum mechanics versus equivalence principle
Ctr Brasileiro Pesquisas Fis, Lab Fis Expt LAFEX, Grp Field Theory Principles 1, BR-22290180 Rio de Janeiro, Brazil
55221669
Conflict between the classical equivalence principle and quantum mechanics
Group of Field Theory from First Principles Centro Brasileiro de Pesquisas Fisicas CBPF, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ
122728528
Photon mass and gravitational deflection
The deflection of a massive photon by an external gravitational field is energy-dependent. Interesting enough, any massive quantum particle, no matter what its spin is, undergoes dispersive deflection in external gravitational fields. Exploiting the dispersive deflection of the quantized massive electromagnetic radiation by the gravitational field of the Sun, we find an upper bound for the photon mass.
122713426
Is the equivalence principle doomed forever to Dante's Inferno on account of quantum mechanics?
It is commonly assumed that the equivalence principle can coexist without conflict with quantum mechanics. We shall argue here that, contrary to popular belief, this principle does not hold in quantum mechanics. We illustrate this point by computing the second-order correction for the scattering of a massive scalar boson by a weak gravitational field, treated as an external field. The resulting cross-section turns out to be mass-dependent. A way out of this dilemma would be, perhaps, to consider gravitation without the equivalence principle. At first sight, this seems to be a too much drastic attitude toward general relativity. Fortunately, the teleparallel version of general relativity — a description of the gravitational interaction by a force similar to the Lorentz force of electromagnetism and that, of course, dispenses with the equivalence principle — is equivalent to general relativity, thus providing a consistent theory for gravitation in the absence of the aforementioned principle.
123610165
Teorias Semiclássica e Efetiva da Gravitação
119299320
Introduction to Quantum Gravity
In this talk, we give a glimpse of the problems with quantum gravity and some possible solutions.