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Papers by Roberto Soldati
Journal of Physics A: Mathematical and General, 2003
We investigate the time evolution of the decay (or ionization) probability of a D-dimensional mod... more We investigate the time evolution of the decay (or ionization) probability of a D-dimensional model atom (D = 1, 2, 3) in the presence of a uniform (i.e., static and homogeneous) background field. The model atom consists in a non-relativistic point particle in the presence of a point-like attractive well. It is shown that the model exhibits infinitely many resonances leading to possible deviations from the naive exponential decay law of the non-decay (or survival) probability of the initial atomic quantum state. Almost stable states exist due to the presence of the attractive interaction, no matter how weak it is. Analytic estimates as well as numerical evaluation of the decay rates are explicitly given and discussed.
Tests of gauge invariance in quantum local gauge field theories
Lecture Notes in Physics, 1990
ABSTRACT
Effective actions of Weyl spinor fields coupled to background complex valued vielbeins
Quantum Phase Factors And" Physical" Gauges
Phys Rev D, 2011
A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a ... more A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a spinless, neutral, massive field in a uniformly accelerated frame with a constant acceleration. The method can be suitably generalized in a straightforward manner to any field with spin and charges.
The functional squeeze operator algebra in Maxwell–Chern–Simons electrodynamics
Theoretical and Mathematical Physics, 2015
ABSTRACT
Introduction to relativistic quantum field theory (a primer for a basic education)
Physics Letters B, 1998
Some new expressions are found, concerning the one-loop effective action of four dimensional mass... more Some new expressions are found, concerning the one-loop effective action of four dimensional massive and massless Dirac fermions in the presence of general uniform electric and magnetic fields, with E · H = 0 and E 2 = H 2 . The rate of pairproduction is computed and briefly discussed.
Lorentz symmetry breaking in models with Wess-Zumino interaction
Propagation of photons and massive vector mesons between a parity breaking medium and vacuum
Journal of High Energy Physics, 2011
Page 1. JHEP11(2011)007 Published for SISSA by Springer Received: September 23, 2011 Accepted: Oc... more Page 1. JHEP11(2011)007 Published for SISSA by Springer Received: September 23, 2011 Accepted: October 21, 2011 Published: November 2, 2011 Propagation of photons and massive vector mesons between a parity breaking medium and vacuum ...
Physics Letters B, 2000
It is shown, by explicit calculation in the axial gauge, that the renormalization group flow for ... more It is shown, by explicit calculation in the axial gauge, that the renormalization group flow for the Wilson loop in perturbation theory does exhibit singularities and consequently it can not eventually reproduce the gauge invariant result, when the infrared cut off is removed.
Physical Review D, 2011
A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a ... more A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a spinless, neutral, massive field in a uniformly accelerated frame with a constant acceleration. The method can be suitably generalized in a straightforward manner to any field with spin and charges.
Journal of Physics A: Mathematical and Theoretical, 2011
A fully algebraic general approach is developed to treat the pairs emission and absorption in the... more A fully algebraic general approach is developed to treat the pairs emission and absorption in the presence of some uniform external background field. In particular, it is shown that the pairs production and annihilation operators, together with the pairs number operator, do actually fulfill the SU(2) functional Lie algebra. As an example of application, the celebrated Schwinger formula is consistently and nicely recovered, within this novel approach, for a Dirac spinor field in the presence of a constant and homogeneous electric field in four spacetime dimensions.
Massive Axial Gauge in the Exact Renormalization Group Approach
International Journal of Modern Physics A, 2001
ABSTRACT
Neutral Massive Spin ½ Particles Emission in a Rindler Space
International Journal of Modern Physics A, 2013
Some new expressions are found, concerning the effective action as a regularized path-integral fo... more Some new expressions are found, concerning the effective action as a regularized path-integral for Dirac's spinors in 3+1 dimensions, in the presence of general uniform (i.e., constant and homogeneous) electric and magnetic fields. The rate of e + e − pairs production is computed and briefly discussed.
It is shown that the quantization of the unphysical degrees of freedom, which leads to the Mandel... more It is shown that the quantization of the unphysical degrees of freedom, which leads to the Mandelstam-Leibbrandt prescription for the infrared spurious singularities in the continuum light cone gauge, does indeed suggest some quite natural recipe to treat the zero modes in the Discretized Light Front Quantization of gauge theories.
Spinning test particle in the manifold of the reference frames
Journal of Physics A: Mathematical and General, 2003
We investigate the time evolution of the decay (or ionization) probability of a D-dimensional mod... more We investigate the time evolution of the decay (or ionization) probability of a D-dimensional model atom (D = 1, 2, 3) in the presence of a uniform (i.e., static and homogeneous) background field. The model atom consists in a non-relativistic point particle in the presence of a point-like attractive well. It is shown that the model exhibits infinitely many resonances leading to possible deviations from the naive exponential decay law of the non-decay (or survival) probability of the initial atomic quantum state. Almost stable states exist due to the presence of the attractive interaction, no matter how weak it is. Analytic estimates as well as numerical evaluation of the decay rates are explicitly given and discussed.
Tests of gauge invariance in quantum local gauge field theories
Lecture Notes in Physics, 1990
ABSTRACT
Effective actions of Weyl spinor fields coupled to background complex valued vielbeins
Quantum Phase Factors And" Physical" Gauges
Phys Rev D, 2011
A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a ... more A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a spinless, neutral, massive field in a uniformly accelerated frame with a constant acceleration. The method can be suitably generalized in a straightforward manner to any field with spin and charges.
The functional squeeze operator algebra in Maxwell–Chern–Simons electrodynamics
Theoretical and Mathematical Physics, 2015
ABSTRACT
Introduction to relativistic quantum field theory (a primer for a basic education)
Physics Letters B, 1998
Some new expressions are found, concerning the one-loop effective action of four dimensional mass... more Some new expressions are found, concerning the one-loop effective action of four dimensional massive and massless Dirac fermions in the presence of general uniform electric and magnetic fields, with E · H = 0 and E 2 = H 2 . The rate of pairproduction is computed and briefly discussed.
Lorentz symmetry breaking in models with Wess-Zumino interaction
Propagation of photons and massive vector mesons between a parity breaking medium and vacuum
Journal of High Energy Physics, 2011
Page 1. JHEP11(2011)007 Published for SISSA by Springer Received: September 23, 2011 Accepted: Oc... more Page 1. JHEP11(2011)007 Published for SISSA by Springer Received: September 23, 2011 Accepted: October 21, 2011 Published: November 2, 2011 Propagation of photons and massive vector mesons between a parity breaking medium and vacuum ...
Physics Letters B, 2000
It is shown, by explicit calculation in the axial gauge, that the renormalization group flow for ... more It is shown, by explicit calculation in the axial gauge, that the renormalization group flow for the Wilson loop in perturbation theory does exhibit singularities and consequently it can not eventually reproduce the gauge invariant result, when the infrared cut off is removed.
Physical Review D, 2011
A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a ... more A new and exact derivation of the Bogoliubov coefficients is obtained for the simplest case of a spinless, neutral, massive field in a uniformly accelerated frame with a constant acceleration. The method can be suitably generalized in a straightforward manner to any field with spin and charges.
Journal of Physics A: Mathematical and Theoretical, 2011
A fully algebraic general approach is developed to treat the pairs emission and absorption in the... more A fully algebraic general approach is developed to treat the pairs emission and absorption in the presence of some uniform external background field. In particular, it is shown that the pairs production and annihilation operators, together with the pairs number operator, do actually fulfill the SU(2) functional Lie algebra. As an example of application, the celebrated Schwinger formula is consistently and nicely recovered, within this novel approach, for a Dirac spinor field in the presence of a constant and homogeneous electric field in four spacetime dimensions.
Massive Axial Gauge in the Exact Renormalization Group Approach
International Journal of Modern Physics A, 2001
ABSTRACT
Neutral Massive Spin ½ Particles Emission in a Rindler Space
International Journal of Modern Physics A, 2013
Some new expressions are found, concerning the effective action as a regularized path-integral fo... more Some new expressions are found, concerning the effective action as a regularized path-integral for Dirac's spinors in 3+1 dimensions, in the presence of general uniform (i.e., constant and homogeneous) electric and magnetic fields. The rate of e + e − pairs production is computed and briefly discussed.
It is shown that the quantization of the unphysical degrees of freedom, which leads to the Mandel... more It is shown that the quantization of the unphysical degrees of freedom, which leads to the Mandelstam-Leibbrandt prescription for the infrared spurious singularities in the continuum light cone gauge, does indeed suggest some quite natural recipe to treat the zero modes in the Discretized Light Front Quantization of gauge theories.
Spinning test particle in the manifold of the reference frames