Chen, Chiang-Mei Kim, Sang Pyo

We study the Schwinger effect in near-extremal Reissner-Nordstr\"{o}m (RN) black holes with electric and/or magnetic charges in the (Anti-) de Sitter (AdS) space. The formula for the Schwinger effect takes a universal form for near-extremal black holes with the near-horizon geometry of ${\rm AdS}_2 \times S^2$ and with the proper radii for the ${\r...

Gurses, Metin Heydarzade, Yaghoub Tekin, Bayram

We show that a nonlinear superposition of two distinct homogenous Friedman-Lemaitre-Robertson-Walker (FLRW) metrics produces an inhomogeneous universe as a solution to the cosmological Einstein equations with a perfect fluid source. In this superposed model, (1) the early and the late stages of the universe are described by two different FLRW metri...

Dengiz, Suat Kilicarslan, Ercan Setare, Mohammad Reza

We apply the Lee-Wald covariant phase space method to the Weyl-invariant Topologically Massive Gravity and compute the corresponding on-shell conserved charges. By using appropriate decay conditions for the existing propagating modes in the near-horizon of a stationary black hole, we obtain the charges generating the asymptotic symmetries. We show ...

Canay, Ezgi Eingorn, Maxim

Two distinct perturbative approaches have been recently formulated within General Relativity, arguing for the screening of gravity in the $\Lambda$CDM Universe. In this paper we compare them and show that the offered screening concepts, each characterized by its own interaction range, can peacefully coexist. Accordingly, we advance a united scheme,...

Bazeia, D. Ferreira, D.A. Moreira, D.C.

This work discuss the construction of braneworld solutions in modified gravity with Lagrange multipliers. We examine the general aspects of the model and present a first order formalism that help us to find analytic solutions of the equations of motion. We also investigate some explicit models, analyse linear stability of the metric and comment on ...

Shababi, Homa Ourabah, Kamel

Many quantum gravity theories predict a minimal length of the order of the Planck length. This prescription implies a numberof modifications in the phase space structure that have consequences on any statistical mechanics approach. We have recently introduced (Shababi and Ourabah, 2019) a formulation of the Thomas–Fermi model in consistency with th...

Casadio, R. Lenzi, M. Ciarfella, A.

We analyse the classical configurations of a bootstrapped Newtonian potential generated by homogeneous spherically symmetric sources in terms of a quantum coherent state. We first compute how the mass and mean wavelength of these solutions scale in terms of the number of quanta in the coherent state. We then note that the classical relation between...

Houthoff, W. Kurov, A. Saueressig, F.

The Asymptotic Safety hypothesis states that the high-energy completion of gravity is provided by an interacting renormalization group fixed point. This implies non-trivial quantum corrections to the scaling dimensions of operators and correlation functions which are characteristic for the corresponding universality class. We use the composite oper...

Fukuda, Masayuki Ohkubo, Yusuke Shiraishi, Jun'ichi

We construct the non-stationary Ruijsenaars functions (affine analogue of the Macdonald functions) in the special case $\kappa=t^{-1/N}$, using the intertwining operators of the Ding-Iohara-Miki algebra (DIM algebra) associated with $N$-fold Fock tensor spaces. By the $S$-duality of the intertwiners, another expression is obtained for the non-stati...

Izmailov, R.N. Karimov, R.Kh. Potapov, A.A. Nandi, K.K.

A well known solution of heterotic string theory is the spinning Kerr–Sen black hole (KSBH) characterized by a string parameter ξ . Kerr black hole is recovered at ξ=0 . The purpose of this paper is to investigate the effect of ξ on a new diagnostic of relative time delay (RTD) to see how the latter deviates from that in general relativity. Assumin...