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Related papers: Type-II Weyl semimetal vs gravastar

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Astrophysical black hole candidates, although long thought to have a horizon, could be horizonless ultra-compact objects. This intriguing possibility is motivated by the black hole information paradox and a plausible fundamental connection…

General Relativity and Quantum Cosmology · Physics 2017-04-26 Bob Holdom , Jing Ren

Weyl fermions of spin $\frac12$ minimally coupled to Einstein's gravity in 4 dimensions cannot be produced purely gravitationally in an expanding Universe at tree level. Surprisingly, as we showed in a recent letter [1], this changes at…

High Energy Physics - Theory · Physics 2024-12-04 Azadeh Maleknejad , Joachim Kopp

Topological Weyl semimetals (WSM), a new state of quantum matter with gapless nodal bulk spectrum and open Fermi arc surface states, have recently sparked enormous interest in condensed matter physics. Based on the symmetry and fermiology,…

Mesoscale and Nanoscale Physics · Physics 2018-01-19 Subhodip Saha , Sumanta Tewari

We propose a quantum model of the Schwarzschild black hole as a quantum mechanics of a system of fermionic degrees of freedom. The system has a constant density of states and a Fermi energy that is inversely proportional to the size of the…

High Energy Physics - Theory · Physics 2024-08-06 Chong-Sun Chu , Rong-Xin Miao

We have found a ferromagnetic Weyl semimetal (WSM) in half metallic Co$_3$Sn$_2$Se$_2$. The three pairs of Weyl points near Fermi level (E$_F$) are derived from nodal lines gapped by spin-orbit coupling (SOC). Though the Weyl points are…

Materials Science · Physics 2018-03-29 Qiunan Xu , Enke Liu , Wujun Shi , Lukas Muechler , Claudia Felser , Yan Sun

We investigate massless fermion production by a two-dimensional dilatonic black hole. Our analysis is based on the Bogoliubov transformation relating the outgoing fermion field observed outside the black hole horizon to the incoming field…

General Relativity and Quantum Cosmology · Physics 2009-10-22 G. Wanders

We consider the thermodynamic properties of an exact black hole solution obtained in Weyl geometric gravity theory, by considering the simplest conformally invariant action, constructed from the square of the Weyl scalar, and the strength…

General Relativity and Quantum Cosmology · Physics 2024-08-05 Muhammad F. A. R. Sakti , Piyabut Burikham , Tiberiu Harko

This is a continuation and generalization of our earlier work on {\it gravastar} in (2+1) anti-de Sitter space-time to 2+1 dimensional solution of charged gravastar. Morphologically this gravastar contains three regions namely: (i) charged…

General Physics · Physics 2015-06-05 Farook Rahaman , A. A. Usmani , Saibal Ray , Safiqul Islam

We explore the realization of distinct analog black hole horizons within tilted Weyl semimetals by comparing two models with contrasting spectral properties. We demonstrate that a spatially varying tilt in the Weyl cone structure creates an…

Mesoscale and Nanoscale Physics · Physics 2026-04-21 M. A. Lozande , E. A. Fajardo

We use the Fock-Ivanenko formalism to obtain the Dirac equation which describes the interaction of a massless 1/2-spin neutral fermion with a gravitational field around a Schwarzschild black hole (BH). We obtain approximated analytical…

General Relativity and Quantum Cosmology · Physics 2011-03-03 Pablo Alejandro Sanchez , Jesus Martin Romero , Mauricio Bellini

Weyl gravity naturally generates effective dark matter and cosmological constant terms as integration constants, eliminating the need to explicitly introduce them into the theory. Additionally, the framework permits three intriguing…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Roman A. Konoplya , Andrii Khrabustovskyi , Jan Kříž , Alexander Zhidenko

Generic black holes in vacuum-de Sitter / Anti-de Sitter spacetimes are studied in quasi-local framework, where the relevant properties are captured in the intrinsic geometry of the null surface (the horizon). Imposing the quasi-local…

General Relativity and Quantum Cosmology · Physics 2018-08-08 Denis Dobkowski-Ryłko , Jerzy Lewandowski , Tomasz Pawłowski

Equilibrium states of black holes can be modelled by isolated horizons. If the intrinsic geometry is spherical, they are called type I while if it is axi-symmetric, they are called type II. The detailed theory of geometry of \emph{quantum}…

General Relativity and Quantum Cosmology · Physics 2010-11-05 Abhay Ashtekar , Jonathan Engle , Chris Van Den Broeck

The recent reported gravitational wave detection motivates one to investigate the properties of different black hole models, especially their behavior under (axial) gravitational perturbation. Here, we study the quasinormal modes of black…

General Relativity and Quantum Cosmology · Physics 2022-08-09 Mehrab Momennia , Seyed Hossein Hendi

Weyl semimetals (WSM) have been discovered in time-reversal symmetric materials, featuring monopoles of Berry's curvature in momentum space. WSM have been distinguished between Type-I and II where the velocity tilting of the cone in the…

Mesoscale and Nanoscale Physics · Physics 2018-01-19 Xu Yang , Kenneth Burch , Ying Ran

In this paper, starting from vortices we are finally lead to a treatment of Fermions as Kerr-Newman type Black Holes wherein we identify the horizon at the particle's Compton wavelength periphery. A naked singularity is avoided and the…

Quantum Physics · Physics 2007-05-23 B. G. Sidharth

We consider finite-sized interfaces of a Weyl semi-metal and show that the corresponding confinement potential is similar to the application of a magnetic field. Among the numerous states, which can be labeled by indices n like in Landau…

Mesoscale and Nanoscale Physics · Physics 2017-03-15 Serguei Tchoumakov , Marcello Civelli , Mark O. Goerbig

Direct observation of black holes is one of the grand challenges in astronomy. If there are super-compact objects which possess unstable circular orbits of photons, however, it may be difficult to distinguish them from black holes by…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Nobuyuki Sakai , Hiromi Saida , Takashi Tamaki

To obtain fermionic quasinormal modes, the Dirac equation for two types of black holes is investigated. For the first type of black hole, the quasinormal modes have continuous spectrum with negative imaginary part that provides the…

High Energy Physics - Theory · Physics 2017-08-02 M. M. Stetsko

We report a combined experimental and theoretical study of the candidate type-II Weyl semimetal MoTe2. Using laser-based angle-resolved photoemission we resolve multiple distinct Fermi arcs on the inequivalent top and bottom (001) surfaces.…

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