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Related papers: Runaway Relaxion from Finite Density

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We study the influence of finite emittance electron bunches in the bubble regime of laser-driven wakefield acceleration onto the microscopic structure of the bunch itself. Using resilient backpropagation (Rprop) to find the equilibrium…

Plasma Physics · Physics 2020-10-07 Lars Reichwein , Johannes Thomas , Alexander Pukhov

We explore the possibility that theories with negative kinetic energy (ghosts) can be meta-stable up to cosmologically long times. In classical mechanics, ghosts undergo spontaneous lockdown rather than run-away if weakly-coupled and…

High Energy Physics - Theory · Physics 2021-06-23 Christian Gross , Alessandro Strumia , Daniele Teresi , Matteo Zirilli

Utilizing a series of N-body simulations, we argue that gravitationally bound stellar clusters of modest population evolve very differently from the picture presented by classical dynamical relaxation theory. The system's most massive stars…

Solar and Stellar Astrophysics · Physics 2015-05-19 Joseph M. Converse , Steven W. Stahler

Dense enough compact objects were recently shown to lead to an exponentially fast increase of the vacuum energy density for some free scalar fields properly coupled to the spacetime curvature as a consequence of a tachyonic-like…

General Relativity and Quantum Cosmology · Physics 2012-11-22 A. G. S. Landulfo , W. C. C. Lima , G. E. A. Matsas , D. A. T. Vanzella

The centres of galaxies host nuclear stellar clusters, supermassive black holes, or both. The origin of this dichotomy is still a mystery. Nuclear stellar clusters are the densest stellar system in the Universe, so they are ideal places for…

Astrophysics of Galaxies · Physics 2023-05-23 M. C. Vergara , A. Escala , D. R. G. Schleicher , B. Reinoso

Full relativistic simulations in three dimensions are known to develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. We present here a method that controls the violation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Pedro Marronetti

It is shown how metastable de Sitter vacua might arise from heterotic M-theory. The balancing of its two non-perturbative effects, open membrane instantons against gaugino condensation on the hidden boundary, which act with opposing forces…

High Energy Physics - Theory · Physics 2011-07-19 Melanie Becker , Gottfried Curio , Axel Krause

We point out that the (pseudo-)conformal Universe scenario may be realized as decay of conformally invariant, metastable vacuum, which proceeds via spontaneous nucleation and subsequent growth of a bubble of a putative new phase. We study…

High Energy Physics - Theory · Physics 2015-05-27 M. Libanov , V. Rubakov

We present a scenario of formation of strange stars due to spin-down of {\it rapidly rotating} neutron stars left after supernova explosions . By assuming a process where the total baryon mass is conserved but the angular momentum is lost…

Astrophysics · Physics 2009-11-10 Nobutoshi Yasutake , Masa-aki Hashimoto , Yoshiharu Eriguchi

Approximately 30% of all massive stars in the Galaxy are runaways with velocities exceeding 30 km/s. Their high speeds allow them to travel ~0.1-1 kpc away from their birth place before they explode at the end of their several Myr…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Charlie Conroy , Kaitlin Kratter

Metastability is a quintessential feature of first order quantum phase transitions, which is lost either by dynamical instability or by nucleating bubbles of a true vacuum through quantum tunneling. By considering a drive across the first…

Statistical Mechanics · Physics 2021-07-28 Aritra Sinha , Titas Chanda , Jacek Dziarmaga

About ten to 20 percent of massive stars may be kicked out of their natal clusters before exploding as supernovae. These "runaway stars" might play a crucial role in driving galactic outflows and enriching the circumgalactic medium with…

We discuss models in which vacua other than our own can be directly observed in the present universe. Models with density-dependent vacuum structure can give rise to `non-lethal'-vacua: vacua with lower energy-density than our vacuum, but…

High Energy Physics - Phenomenology · Physics 2019-10-02 Anson Hook , Junwu Huang

If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of…

High Energy Physics - Theory · Physics 2015-05-26 Ali Masoumi

Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and…

Astrophysics of Galaxies · Physics 2015-05-13 Benjamin C. Bromley , Scott J. Kenyon , Warren R. Brown , Margaret J. Geller

We construct relativistic equilibrium models of differentially rotating neutron stars and show that they can support significantly more mass than their nonrotating or uniformly rotating counterparts. We dynamically evolve such…

Astrophysics · Physics 2011-05-05 Thomas W. Baumgarte , Stuart L. Shapiro , Masaru Shibata

We study a far-from-equilibrium system of interacting particles, hopping between sites of a 1d lattice with a rate which increases with the number of particles at interacting sites. We find that clusters of particles, which initially…

Statistical Mechanics · Physics 2015-05-30 Bartlomiej Waclaw , Martin R. Evans

As rotating neutron stars slow down, the pressure and the density in the core region increase due to the decreasing centrifugal forces and phase transitions may occur in the center. We extract the analytic behavior near the critical angular…

Astrophysics · Physics 2008-11-26 H. Heiselberg , M. Hjorth-Jensen

We study the dynamical evolution of a large amplitude r-mode by numerical simulations. R-modes in neutron stars are unstable growing modes, driven by gravitational radiation reaction. In these simulations, r-modes of amplitude unity or…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Philip Gressman , Lap-Ming Lin , Wai-Mo Suen , N. Stergioulas , John L. Friedman

We present an investigation of the known sample of runaway stars. The orbits of these stars are traced back to their origin in the Galactic disc. The velocity distribution of these stars is compared to theoretical predictions. We conclude…

Solar and Stellar Astrophysics · Physics 2011-09-20 Ralf Napiwotzki , Manuel D. V. Silva