Zobrazeno 1 - 10
of 579
pro vyhledávání: '"Tsujikawa, Shinji"'
Autor:
De Felice, Antonio, Tsujikawa, Shinji
We show that nonsingular black holes realized in nonlinear electrodynamics are always prone to Laplacian instability around the center because of a negative squared sound speed in the angular direction. This is the case for both electric and magnetic
Externí odkaz:
http://arxiv.org/abs/2410.00314
In a subclass of generalized Proca theories where a cubic vector Galileon term breaks the $U(1)$ gauge invariance, it is known that there are static and spherically symmetric black hole (BH) solutions endowed with nonvanishing temporal and longitudin
Externí odkaz:
http://arxiv.org/abs/2409.15606
We revisit one-loop corrections to the power spectrum of curvature perturbations $\zeta$ in an inflationary scenario containing a transient ultra-slow-roll (USR) period. In Ref.[1], it was argued that one-loop corrections to the power spectrum of $\z
Externí odkaz:
http://arxiv.org/abs/2407.19742
In Einstein-Aether theories with a timelike unit vector field, we study the linear stability of static and spherically symmetric black holes against both even- and odd-parity perturbations. For this purpose, we formulate a gauge-invariant black hole
Externí odkaz:
http://arxiv.org/abs/2407.00287
Publikováno v:
Phys. Rev. D 110, 044024 (2024)
In Einstein-Aether gravity, we revisit the issue of linear stabilities of black holes against odd-parity perturbations on a static and spherically symmetric background. In this theory, superluminal propagation is allowed and there is a preferred time
Externí odkaz:
http://arxiv.org/abs/2405.14071
Publikováno v:
JCAP 07 (2024) 022
Horndeski's vector-tensor (HVT) gravity is described by a Lagrangian in which the field strength $F_{\mu \nu}=\partial_{\mu} A_{\nu}-\partial_{\nu} A_{\mu}$ of a vector field $A_{\mu}$ interacts with a double dual Riemann tensor $L^{\mu \nu \alpha \b
Externí odkaz:
http://arxiv.org/abs/2404.09377
Publikováno v:
Phys. Lett. B 856 (2024) 138962
We revisit the properties of total time-derivative terms as well as terms proportional to the free equation of motion (EOM) in a Schwinger-Keldysh formalism. They are relevant to the correct calculation of correlation functions of curvature perturbat
Externí odkaz:
http://arxiv.org/abs/2403.16022
Publikováno v:
Phys. Rev. D 109, 104057 (2024)
We study the linear stability of spontaneously scalarized black holes (BHs) induced by a scalar field $\phi$ coupled to a Gauss-Bonnet (GB) invariant $R_{\rm GB}^2$. For the scalar-GB coupling $\xi(\phi)=(\eta/8) (\phi^2+\alpha \phi^4)$, where $\eta$
Externí odkaz:
http://arxiv.org/abs/2403.10048
Autor:
De Felice, Antonio, Tsujikawa, Shinji
Publikováno v:
Phys. Lett. B 855 (2024) 138808
The axion-photon coupling allows the existence of a magnetically and electrically charged black hole (BH) solution endowed with a pseudo-scalar hair. For the Reissner-Nordstrom BH with a given total charge and mass, it is known that the quasinormal m
Externí odkaz:
http://arxiv.org/abs/2402.08868
Publikováno v:
Phys. Rev. D 110, 083506 (2024)
Primordial magnetogenesis is an intriguing possibility to explain the origin of intergalactic magnetic fields (IGMFs). However, the baryon isocurvature problem has recently been pointed out, ruling out all magnetogenesis models operating above the el
Externí odkaz:
http://arxiv.org/abs/2312.07938