scholarly journals Group theoretical approach to quantum fields in de Sitter space, I. The principal series

2006 ◽  
Vol 2006 (08) ◽  
pp. 082-082 ◽  
Author(s):  
Euihun Joung ◽  
Jihad Mourad ◽  
Renaud Parentani
Keyword(s):  
Theoretical Approach ◽  
Principal Series ◽  
De Sitter Space ◽  
Quantum Fields ◽  
De Sitter

Classical and quantum fields in de Sitter space

1969 ◽  
Vol 64 (3) ◽  
pp. 669-714 ◽  
Author(s):  
G. Börner ◽  
H. P. Dürr
Keyword(s):  
De Sitter Space ◽  
Quantum Fields ◽  
De Sitter

scholarly journals LECTURE NOTES ON INTERACTING QUANTUM FIELDS IN DE SITTER SPACE

2014 ◽  
Vol 23 (01) ◽  
pp. 1430001 ◽  
Author(s):  
E. T. AKHMEDOV
Keyword(s):  
De Sitter Space ◽  
The Self ◽  
Field Theories ◽  
Tree Level ◽  
Main Concern ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Quantum Fields ◽  
De Sitter ◽  
Invariant States

We discuss peculiarities of quantum fields in de Sitter (dS) space on the example of the self-interacting massive real scalar, minimally coupled to the gravity background. Nonconformal quantum field theories (QFTs) in dS space show very special infrared behavior, which is not shared by quantum fields neither in flat nor in anti-dS space: in dS space loops are not suppressed in comparison with tree level contributions because there are strong infrared corrections. That is true even for massive fields. Our main concern is the interrelation between these infrared effects, the invariance of the QFT under the dS isometry and the (in)stability of dS invariant states (and of dS space itself) under nonsymmetric perturbations.

scholarly journals Canonical quantization of the covariant fields on de Sitter space–times

2018 ◽  
Vol 33 (08) ◽  
pp. 1830007 ◽  
Author(s):  
Ion I. Cotaescu
Keyword(s):  
Isometry Group ◽  
Canonical Quantization ◽  
Principal Series ◽  
De Sitter Space ◽  
Fermion Mass ◽  
Dirac Field ◽  
De Sitter ◽  
Covariant Quantum ◽  
Covariant Representations ◽  
Casimir Operators

The properties of the covariant quantum fields on de Sitter space–times are investigated focusing on the isometry generators and Casimir operators in order to establish the equivalence among the covariant representations and the unitary irreducible ones of the de Sitter isometry group. For the Dirac quantum field, it is shown that the spinor covariant representation, transforming the Dirac field under de Sitter isometries, is equivalent with a direct sum of two unitary irreducible representations of the [Formula: see text] group, transforming alike the particle and antiparticle field operators in momentum representation. Their basis generators and Casimir operators are written down finding that the covariant representations are equivalent with unitary irreducible ones from the principal series whose canonical weights are determined by the fermion mass and spin.

HOW HOT IS THE DE SITTER SPACE?

1996 ◽  
Vol 10 (13n14) ◽  
pp. 1507-1520 ◽  
Author(s):  
H. NARNHOFER ◽  
I. PETER ◽  
W. THIRRING
Keyword(s):  
Vector Field ◽  
Killing Vector ◽  
De Sitter Space ◽  
Killing Vector Field ◽  
Quantum Fields ◽  
De Sitter

We show that the unique invariant locally Minkowskian state of quantum fields in de Sitter space M has for an observer moving along with a Killing vector field a temperature [Formula: see text] where R is the radius of M and a his acceleration. States with another temperature cannot be locally Minkowskian all over M.

scholarly journals SPONTANEOUS DECAY OF THE EFFECTIVE COSMOLOGICAL CONSTANT

1998 ◽  
Vol 13 (07) ◽  
pp. 571-580 ◽  
Author(s):  
MURAT ÖZER ◽  
M. O. TAHA
Keyword(s):  
Cosmological Constant ◽  
De Sitter Space ◽  
Space Time ◽  
Time Dependent ◽  
Spontaneous Decay ◽  
Quantum Fields ◽  
De Sitter ◽  
Initial Value ◽  
Effective Time ◽  
Effective Cosmological Constant

We discuss the notion that quantum fields may induce an effective time-dependent cosmological constant which decays from a large initial value. It is shown that such cosmological models are viable in a non-de Sitter space–time.

Gravitational shock waves and quantum fields in de Sitter space

1993 ◽  
Vol 47 (8) ◽  
pp. 3323-3329
Author(s):  
M. Hotta ◽  
M. Tanaka
Keyword(s):  
Shock Waves ◽  
De Sitter Space ◽  
Quantum Fields ◽  
De Sitter

scholarly journals An invitation to the principal series

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Tarek Anous ◽  
Jim Skulte
Keyword(s):  
Isometry Group ◽  
Hamiltonian Formulation ◽  
Series Representation ◽  
Principal Series ◽  
Scalar Fields ◽  
De Sitter Space ◽  
Late Time ◽  
De Sitter ◽  
Principal Series Representation ◽  
Massive Scalar Field

Scalar unitary representations of the isometry group of dd-dimensional de Sitter space SO(1,d)SO(1,d) are labeled by their conformal weights \DeltaΔ. A salient feature of de Sitter space is that scalar fields with sufficiently large mass compared to the de Sitter scale 1/\ell1/ℓ have complex conformal weights, and physical modes of these fields fall into the unitary continuous principal series representation of SO(1,d)SO(1,d). Our goal is to study these representations in d=2d=2, where the relevant group is SL(2,\mathbb{R})SL(2,ℝ). We show that the generators of the isometry group of dS_22 acting on a massive scalar field reproduce the quantum mechanical model introduced by de Alfaro, Fubini and Furlan (DFF) in the early/late time limit. Motivated by the ambient dS_22 construction, we review in detail how the DFF model must be altered in order to accommodate the principal series representation. We point out a difficulty in writing down a classical Lagrangian for this model, whereas the canonical Hamiltonian formulation avoids any problem. We speculate on the meaning of the various de Sitter invariant vacua from the point of view of this toy model and discuss some potential generalizations.

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