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Related papers: Semiclassical instability of dynamical warp drives

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The semiclassical collapse of a homogeneous sphere of dust is studied. After identifying the independent dynamical variables, the system is canonically quantised and coupled equations describing matter (dust) and gravitation are obtained.…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Roberto Casadio , Giovanni Venturi

Critical gravitational collapse offers a unique window into regimes of arbitrarily high curvature, culminating in a naked singularity arising from smooth initial data -- thus providing a dynamical counterexample to weak cosmic censorship.…

General Relativity and Quantum Cosmology · Physics 2026-05-18 Marija Tomašević , Chih-Hung Wu

The dynamics of a spherically symmetric thin shell with arbitrary rest mass and surface tension interacting with a central black hole is studied. A careful investigation of all classical solutions reveals that the value of the radius of the…

General Relativity and Quantum Cosmology · Physics 2011-09-09 P. Hajicek , J. Bicak

A coherent picture of the quantum mechanics of a collapse-formed, evaporating black hole is presented. In a distant frame, semiclassical theory in the zone describes microscopic dynamics of only the "hard modes," the modes that are hard…

High Energy Physics - Theory · Physics 2019-04-17 Yasunori Nomura

Supersymmetric black holes in five-dimensional gauged supergravity must necessarily be rotating, and so in order to study the passage to black holes away from supersymmetry, it is of great interest to obtain non-extremal black holes that…

High Energy Physics - Theory · Physics 2008-11-26 Z. W. Chong , M. Cvetic , H. Lu , C. N. Pope

Magnetic fields grow quickly even at early cosmological times, suggesting the action of a small-scale dynamo (SSD) in the interstellar medium of galaxies. Many studies have focused on idealized turbulent driving of the SSD. Here we simulate…

Astrophysics of Galaxies · Physics 2021-04-07 Frederick A. Gent , Mordecai-Mark Mac Low , Maarit J. Kapyla , Nishant K. Singh

Recently probabilistic hysteresis in isolated Hamiltonian systems of ultracold atoms has been studied in the limit of large particle numbers, where a semiclassical treatment is adequate. The origin of irreversibility in these sweep…

Quantum Physics · Physics 2020-05-20 Ralf Bürkle , James R. Anglin

The cosmological remnants of a first-order phase transition generally depend on the perturbations that the walls of expanding bubbles originate in the plasma. Several of the formation mechanisms occur when bubbles collide and lose their…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-17 Leonardo Leitao , Ariel Megevand

Semiconvection occurs in regions of stars and planets that are unstable to overturning convection according to the Schwarzschild criterion, yet stable according to the Ledoux criterion. Previous simulations in Cartesian boxes have advanced…

Solar and Stellar Astrophysics · Physics 2025-03-19 J. R. Fuentes

Looking at current proposals of so-called `warp drive spacetimes', they appear to employ General Relativity only at an elementary level. A number of strong restrictions are imposed such as flow-orthogonality of the spacetime foliation,…

General Relativity and Quantum Cosmology · Physics 2025-09-05 Hamed Barzegar , Thomas Buchert

The nonintegrable Hamiltonian dynamics of particles placed in a symmetric, spatially periodic potential and subjected to a periodically varying field is explored. Such systems can exhibit a rich diversity of unusual transport features. In…

Chaotic Dynamics · Physics 2008-07-10 D. Hennig , L. Schimansky-Geier , P. Hänggi

To gain more insights about what could be the source of the Alcubierre warp drive, a technique designed to find an orthogonal basis from the metric expression is used. It is deduced that exotic fluids can produce the same stress-energy…

General Relativity and Quantum Cosmology · Physics 2020-12-21 Willie Béatrix-Drouhet

We argue that black holes microstates leave an imprint on the gravitational vacuum through their virtual fluctuations. This imprint yields a power law fall off -- rather than an exponential fall off -- for the entanglement of planck scale…

High Energy Physics - Theory · Physics 2025-05-16 Samir D. Mathur

New singularity theorems are derived for generic warped-product spacetimes of any dimension. The main purpose is to analyze the stability of (compact or large) extra dimensions against dynamical perturbations. To that end, the base of the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Nastassja Cipriani , José M. M. Senovilla

Orbiting disks may exhibit bends due to a misalignment between the angular momentum of the inner and outer regions of the disk. We begin a systematic simulational inquiry into the physics of warped disks with the simplest case: the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Kareem A. Sorathia , Julian H. Krolik , John F. Hawley

The mechanisms which give rise to Hawking radiation are revealed by analyzing in detail pair production in the presence of horizons. In preparation for the black hole problem, three preparatory problems are dwelt with at length: pair…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Robert Brout , Serge Massar , Renaud Parentani , Philippe Spindel

The supersymmetry arises in certain theories of fermions coupled to gauge fields and gravity in a spacetime of 11 dimensions. The dynamical brane background has mainly been studied for the class of purely bosonic solutions only, but recent…

High Energy Physics - Theory · Physics 2017-12-06 Kengo Maeda , Kunihito Uzawa

Emergent modified gravity is a canonical theory based on general covariance where the spacetime is not fundamental, but rather an emergent object. This feature allows for modifications of the classical theory and can be used to model new…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Erick I. Duque

Semiclassical mechanics of systems with first-class constraints is developed. Starting from the quantum theory, one investigates such objects as semiclassical states and observables, semiclassical inner product, semiclassical gauge…

High Energy Physics - Theory · Physics 2007-05-23 Oleg Shvedov

In this work, we consider a semiclassical description of the spherically symmetric gravitational collapse with a massless scalar field. In particular, we employ an effective scenario provided by holonomy corrections from loop quantum…

General Relativity and Quantum Cosmology · Physics 2014-05-21 Yaser Tavakoli , Joao Marto , Andrea Dapor