Quantization on a Classical Background Using Bogolyubov Variables

2021 ◽  
Vol 18 (7) ◽  
pp. 709-715
Author(s):  
M. V. Ostanina ◽  
P. A. Tomasi-Vshivtseva
Keyword(s):  
2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Gourav Banerjee ◽  
Sudip Karan ◽  
Binata Panda

Abstract We study one-loop covariant effective action of “non-minimally coupled” $$ \mathcal{N} $$ N = 1, d = 4 Einstein-Maxwell supergravity theory by heat kernel tool. By fluctuating the fields around the classical background, we study the functional determinant of Laplacian differential operator following Seeley-DeWitt technique of heat kernel expansion in proper time. We then compute the Seeley-DeWitt coefficients obtained through the expansion. A particular Seeley-DeWitt coefficient is used for determining the logarithmic correction to Bekenstein-Hawking entropy of extremal black holes using quantum entropy function formalism. We thus determine the logarithmic correction to the entropy of Kerr-Newman, Kerr and Reissner-Nordström black holes in “non-minimally coupled” $$ \mathcal{N} $$ N = 1, d = 4 Einstein-Maxwell supergravity theory.


Euphrosyne ◽  
1998 ◽  
Vol 26 ◽  
pp. 121-136
Author(s):  
José António Segurado Campos

2014 ◽  
Vol 29 (30) ◽  
pp. 1430034 ◽  
Author(s):  
Ilya L. Shapiro ◽  
Ana M. Pelinson ◽  
Filipe de O. Salles

Understanding the role of higher derivatives is probably one of the most relevant questions in quantum gravity theory. Already at the semiclassical level, when gravity is a classical background for quantum matter fields, the action of gravity should include fourth derivative terms to provide renormalizability in the vacuum sector. The same situation holds in the quantum theory of metric. At the same time, including the fourth derivative terms means the presence of massive ghosts, which are gauge-independent massive states with negative kinetic energy. At both classical and quantum level such ghosts violate stability and hence the theory becomes inconsistent. Several approaches to solve this contradiction were invented and we are proposing one more, which looks simpler than those what were considered before. We explore the dynamics of the gravitational waves on the background of classical solutions and give certain arguments that massive ghosts produce instability only when they are present as physical particles. At least on the cosmological background one can observe that if the initial frequency of the metric perturbations is much smaller than the mass of the ghost, no instabilities are present.


2017 ◽  
Vol 32 (35) ◽  
pp. 1750181
Author(s):  
V. M. Khatsymovsky

We consider the Faddeev formulation of general relativity (GR), which can be characterized by a kind of d-dimensional tetrad (typically d = 10) and a non-Riemannian connection. This theory is invariant w.r.t. the global, but not local, rotations in the d-dimensional space. There can be configurations with a smooth or flat metric, but with the tetrad that changes abruptly at small distances, a kind of “antiferromagnetic” structure. Previously, we discussed a first-order representation for the Faddeev gravity, which uses the orthogonal connection in the d-dimensional space as an independent variable. Using the discrete form of this formulation, we considered the spectrum of (elementary) area. This spectrum turns out to be physically reasonable just on a classical background with large connection like rotations by [Formula: see text], that is, with such an “antiferromagnetic” structure. In the discrete first-order Faddeev gravity, we consider such a structure with periodic cells and large connection and strongly changing tetrad field inside the cell. We show that this system in the continuum limit reduces to a generalization of the Faddeev system. The action is a sum of related actions of the Faddeev type and is still reduced to the GR action.


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