scholarly journals DIRAC–COULOMB SCATTERING WITH PLANE WAVE ENERGY EIGENSPINORS ON DE SITTER EXPANDING UNIVERSE

2008 ◽  
Vol 23 (09) ◽  
pp. 1351-1359 ◽  
Author(s):  
ION I. COTĂESCU ◽  
COSMIN CRUCEAN
Keyword(s):  
Dirac Equation ◽  
Plane Wave ◽  
Wave Energy ◽  
De Sitter Space ◽  
Space Time ◽  
Dirac Field ◽  
Coulomb Scattering ◽  
Final States ◽  
De Sitter ◽  
Scattering Process

The lowest order contribution of the amplitude of Dirac–Coulomb scattering in de Sitter space–time is calculated assuming that the initial and final states of the Dirac field are described by exact solutions of the free Dirac equation on de Sitter space–time with a given energy and helicity. We find that the total energy is conserved in the scattering process.

scholarly journals COULOMB SCATTERING OF THE DIRAC FERMIONS ON DE SITTER EXPANDING UNIVERSE

2007 ◽  
Vol 22 (34) ◽  
pp. 2573-2585 ◽  
Author(s):  
COSMIN CRUCEAN
Keyword(s):  
Dirac Equation ◽  
Exact Solutions ◽  
Cross Section ◽  
Dirac Field ◽  
Coulomb Scattering ◽  
De Sitter Spacetime ◽  
Dirac Fermions ◽  
Final States ◽  
De Sitter ◽  
Sitter Spacetime

The lowest order contribution of the amplitude of the Dirac–Coulomb scattering in de Sitter spacetime is calculated assuming that the initial and final states of the Dirac field are described by exact solutions of the free Dirac equation on de Sitter spacetime with a given momentum and helicity. One studies the difficulties that arises when one passes from the amplitude to cross section.

scholarly journals NEW DIRAC QUANTUM MODES IN MOVING FRAMES OF THE DE SITTER SPACE–TIME

2008 ◽  
Vol 23 (22) ◽  
pp. 3707-3720 ◽  
Author(s):  
ION I. COTĂESCU ◽  
COSMIN CRUCEAN
Keyword(s):  
Quantum Mechanics ◽  
Dirac Equation ◽  
Complete System ◽  
Plane Waves ◽  
De Sitter Space ◽  
Space Time ◽  
Principal Result ◽  
Moving Frames ◽  
De Sitter ◽  
Schrödinger Picture

Recently a new time-evolution picture of the Dirac quantum mechanics was defined in charts with spatially flat Robertson–Walker metrics, under the name of Schrödinger picture (I. I. Cotăescu, Mod. Phys. Lett. A22, 2965 (2007)). In the present paper, new Dirac quantum modes are found in moving charts of the de Sitter space–time using the technical advantages offered by this picture. The principal result is a new set of energy eigenspinors which behave as polarized plane waves and form a complete system of orthonormalized solutions of the free Dirac equation.

scholarly journals REDUCTION FORMALISM FOR DIRAC FERMIONS ON DE SITTER SPACE–TIME

2008 ◽  
Vol 23 (07) ◽  
pp. 1075-1087 ◽  
Author(s):  
COSMIN CRUCEAN ◽  
RADU RACOCEANU
Keyword(s):  
Perturbation Theory ◽  
Dirac Equation ◽  
Exact Solutions ◽  
Scattering Amplitude ◽  
De Sitter Space ◽  
Space Time ◽  
Green Functions ◽  
Dirac Fermions ◽  
De Sitter

The reduction formulas for Dirac fermions is derived using the exact solutions of free Dirac equation on de Sitter space–time. In the framework of the perturbation theory one studies the Green functions and derives the scattering amplitude in the first orders of perturbation theory.

scholarly journals EXPLICIT DERIVATION OF THE FLUCTUATION-DISSIPATION RELATION OF THE VACUUM NOISE IN THE N-DIMENSIONAL DE SITTER SPACE–TIME

2001 ◽  
Vol 16 (16) ◽  
pp. 2841-2857 ◽  
Author(s):  
T. MURATA ◽  
K. TSUNODA ◽  
K. YAMAMOTO
Keyword(s):  
Equations Of Motion ◽  
De Sitter Space ◽  
Space Time ◽  
Dirac Field ◽  
De Sitter ◽  
Fluctuation Dissipation ◽  
Dissipative Coefficient ◽  
Retarded Green Function ◽  
Kms Condition ◽  
Explicit Derivation

Motivated by a recent work by Terashima (Phys. Rev.D60, 084001), we revisit the fluctuation-dissipation (FD) relation between the dissipative coefficient of a detector and the vacuum noise of fields in curved space–time. In an explicit manner we show that the dissipative coefficient obtained from classical equations of motion of the detector and the scalar (or Dirac) field satisfies the FD relation associated with the vacuum noise of the field, which demonstrates that Terashima's prescription works properly in the N-dimensional de Sitter space–time. This practice is useful not only to reconfirm the validity of the use of the retarded Green function to evaluate the dissipative coefficient from the classical equations of motion but also to understand why the derivation works properly, which is discussed in connection with previous investigations on the basis of the Kubo–Martin–Schwinger (KMS) condition. Possible application to black hole space–time is also briefly discussed.

Noncommutative scalar field in de Sitter space–time and pair creation process

2021 ◽  
Vol 36 (02) ◽  
pp. 2150011
Author(s):  
Nabil Mehdaoui ◽  
Lamine Khodja ◽  
Salah Haouat
Keyword(s):  
Scalar Field ◽  
Chemical Potential ◽  
De Sitter Space ◽  
Space Time ◽  
Pair Creation ◽  
De Sitter ◽  
Creation Process ◽  
Scalar Particles ◽  
Constant Electromagnetic Field

In this work, we address the process of pair creation of scalar particles in [Formula: see text] de Sitter space–time in presence of a constant electromagnetic field by applying the noncommutativity on the scalar field up to first-order in [Formula: see text]. We calculate the density of particles created in the vacuum by the mean of the Bogoliubov transformations. In contrast to a previous result, we show that noncommutativity contributes to the pair creation process. We find that the noncommutativity plays the same role of chemical potential and gives an important interest for studies at high energies.

Quantum field theory in anti-de Sitter space-time

1978 ◽  
Vol 18 (10) ◽  
pp. 3565-3576 ◽  
Author(s):  
S. J. Avis ◽  
C. J. Isham ◽  
D. Storey
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
De Sitter Space ◽  
Space Time ◽  
Quantum Field ◽  
De Sitter
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