Zobrazeno 1 - 10
of 651
pro vyhledávání: '"Andréi, O"'
We discuss peculiarities of the Schwinger--DeWitt technique for quantum effective action, associated with the origin of dimensionally regularized double-pole divergences of the one-loop functional determinant for massive Proca model in a curved space
Externí odkaz:
http://arxiv.org/abs/2408.16174
We suggest a new technique of the asymptotic heat kernel expansion for minimal higher derivative operators of a generic $2M$-th order, $F(\nabla)=(-\Box)^M+\cdots$, in the background field formalism of gauge theories and quantum gravity. This techniq
Externí odkaz:
http://arxiv.org/abs/2408.10990
We investigate the renormalization group flow of projectable Horava gravity in $(3+1)$ dimensions generated by marginal operators with respect to the Lifshitz scaling. The flow possesses a number of asymptotically free fixed points. We find a family
Externí odkaz:
http://arxiv.org/abs/2310.07841
Autor:
Barvinsky, Andrei O., Kolganov, Nikita
Motivated by cosmological Hartle-Hawking and microcanonical density matrix prescriptions for the quantum state of the Universe we develop Schwinger-Keldysh in-in formalism for generic nonequilibrium dynamical systems with the initial density matrix.
Externí odkaz:
http://arxiv.org/abs/2309.03687
Autor:
Barvinsky, Andrei O., Camargo, Guilherme H. S., Kalugin, Alexei E., Ohta, Nobuyoshi, Shapiro, Ilya L.
The finite local conformally non-invariant $R^2$-term emerges in the one-loop effective action of the model of quantum gravity based on the Weyl-squared classical action. This term is related to the $\Box R$ contribution to the conformal anomaly, whi
Externí odkaz:
http://arxiv.org/abs/2308.05251
Autor:
Barvinsky, Andrei O.
We give a review of UV renormalization of Ho\v{r}ava gravity (HG) models introduced as a remedy against violation of unitarity in quantum gravity theory. Projectable and non-projectable low-dimensional HG models and the spectra of their physical degr
Externí odkaz:
http://arxiv.org/abs/2301.13580
We discuss applications of perturbative quantum gravity in the theory of very early quantum Universe and quantum cosmology. Consistency of the theoretical formalism for quantum effects of matter and correspondence with observational status of modern
Externí odkaz:
http://arxiv.org/abs/2212.13077
Publikováno v:
Phys. Rev. D 105, 065013 (2022)
We build a systematic calculational method for the covariant expansion of the two-point heat kernel $\hat K(\tau|x,x')$ for generic minimal and non-minimal differential operators of any order. This is the expansion in powers of dimensional background
Externí odkaz:
http://arxiv.org/abs/2112.03062
We derive the full set of beta functions for the marginal essential couplings of projectable Horava gravity in (3 + 1)-dimensional spacetime. To this end we compute the divergent part of the one-loop effective action in static background with arbitra
Externí odkaz:
http://arxiv.org/abs/2110.14688
Publikováno v:
JHEP 2106 (2021) 180
By using holographic methods, the radii of convergence of the hydrodynamic shear and sound dispersion relations were previously computed in the ${\cal N} = 4$ supersymmetric Yang-Mills theory at infinite 't Hooft coupling and infinite number of colou
Externí odkaz:
http://arxiv.org/abs/2104.11035