Comment on: “ ‘Massive’ vector field in de Sitter space” [J. Math. Phys. 41, 5920 (2000)]

2002 ◽  
Vol 43 (12) ◽  
pp. 6379-6379 ◽  
Author(s):  
T. Garidi ◽  
J.-P. Gazeau ◽  
M. V. Takook
2000 ◽  
Vol 41 (9) ◽  
pp. 5920-5933 ◽  
Author(s):  
J-P. Gazeau ◽  
M. V. Takook

2017 ◽  
Vol 35 (3) ◽  
pp. 79-93
Author(s):  
Tugba Mert ◽  
Baki Karlıga

In this paper; using the angle between unit normal vector field of surfaces and a fixed spacelike axis in R₁⁴, we develop two class of spacelike surface which are called constant timelike angle surfaces with timelike and spacelike axis in de Sitter space S₁³.


2013 ◽  
Vol 28 (05n06) ◽  
pp. 1350011
Author(s):  
G. ALENCAR ◽  
I. GUEDES ◽  
R. R. LANDIM ◽  
R. N. COSTA FILHO

In this work, we investigate the quantum theory of the Kalb–Ramond fields propagating in D-dimensional de Sitter space–times using the dynamic invariant method developed by Lewis and Riesenfeld [J. Math. Phys.10, 1458 (1969)] to obtain the solution of the time-dependent Schrödinger equation. The wave function is written in terms of a c-number quantity satisfying the Milne–Pinney equation, whose solution can be expressed in terms of two independent solutions of the respective equation of motion. We obtain the exact solution for the quantum Kalb–Ramond field in the de Sitter background and discuss its relation with the Cremmer–Scherk–Kalb–Ramond model.


1996 ◽  
Vol 10 (13n14) ◽  
pp. 1507-1520 ◽  
Author(s):  
H. NARNHOFER ◽  
I. PETER ◽  
W. THIRRING

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.


2011 ◽  
Vol 26 (28) ◽  
pp. 2149-2158 ◽  
Author(s):  
R. CASADIO ◽  
S. CHIODINI ◽  
A. ORLANDI ◽  
G. ACQUAVIVA ◽  
R. DI CRISCIENZO ◽  
...  

We give an interpretation of the temperature in de Sitter universe in terms of a dynamical Unruh effect associated with the Hubble sphere. As with the quantum noise perceived by a uniformly accelerated observer in static spacetimes, observers endowed with a proper motion can in principle detect the effect. In particular, we study a "Kodama observer" as a two-field Unruh detector for which we show the effect is approximately thermal. We also estimate the back-reaction of the emitted radiation and find trajectories associated with the Kodama vector field are stable.


2012 ◽  
Vol 90 (7) ◽  
pp. 667-674 ◽  
Author(s):  
S. Jamal ◽  
A.H. Kara ◽  
Ashfaque H. Bokhari

In this paper, we complement the analysis involving the “fundamental” solutions of the Klein–Gordon equation in de Sitter space–times given by Yagdjian and A. Galstian (Comm. Math. Phys. 285, 293 (2009); Discrete and Continuous Dynamical Systems S, 2(3), 483 (2009)). Using the symmetry generators, we classify and reduce the underlying equations and show how this process may lead to exact solutions by quadratures.


2019 ◽  
Vol 28 (04) ◽  
pp. 1950064 ◽  
Author(s):  
A. Oliveros ◽  
Marcos A. Jaraba

Inspired by the Generalized Proca Theory, we study a vector–tensor model of inflation with massive vector fields and derivative self-interactions. The action under consideration contains a usual Maxwell-like kinetic term, a general potential term and a term with nonminimal derivative coupling between the vector field and gravity, via the dual Riemann tensor. In this theory, the last term contains a free parameter, [Formula: see text], which quantifies the nonminimal derivative coupling. In this scenario, taking into account a spatially flat Friedmann–Robertson–Walker (FRW) universe and a general vector field, we obtain the general expressions for the equation of motion and the total energy–momentum tensor. Choosing a Proca-type potential, a suitable inflationary regimen driven by massive vector fields is studied. In this model, the isotropy of expansion is guaranteed by considering a triplet of orthogonal vector fields. In order to obtain an inflationary solution with this model, the quasi de Sitter expansion was considered. In this case, the vector field behaves as a constant. Finally, slow-roll analysis is performed and slow-roll conditions are defined for this model, which, for suitable constraints of the model parameters, can give the required number of e-folds for sufficient inflation.


Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 606 ◽  
Author(s):  
Selçuk Baş

This paper presents a new type of spacelike magnetic curves associated with the Sabban vector field defined in the Minkowski space. In this approach, some geometrical and physical features of the moving charged particle corresponding to the spacelike magnetic curves are identified. An entire characterization is developed for spacelike spherical magnetic curves, denoting particularly the changes of their energy with respect to time, the influence of the magnetic force on them, and the existence condition for the uniformity of these curves.


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