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Selected Works

2017

Black holes

Articles 1 - 7 of 7

Full-Text Articles in Physics

Black Holes, Wormholes, And Extra Dimensions, Maria Babiuc-Hamilton Dec 2017

Black Holes, Wormholes, And Extra Dimensions, Maria Babiuc-Hamilton

Maria C. Babiuc-Hamilton

No abstract provided.


New Numerical Code For Black Hole Initial Data, Maria Babiuc-Hamilton Dec 2017

New Numerical Code For Black Hole Initial Data, Maria Babiuc-Hamilton

Maria C. Babiuc-Hamilton

There are no exact solutions of Einstein Equations that describes a bound system radiating gravitational waves. One needs to resort to numerical simulations, or analytical approximation methods. Current methods to constrained initial data exhibit junk radiation and ambiguities about constrained and free data. It was mathematically proved that given the correct initial data, Einstein equation will yield the expected solution.


Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, Jonas R. Mureika, Euro Spallucci Sep 2017

Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, Jonas R. Mureika, Euro Spallucci

Jonas Mureika

Tensor and scalar unparticle couplings to matter have been shown to enhance gravitational interactions and provide corrections to the Schwarzschild metric and associated black hole structure. We derive an exact solution to the Einstein equations for vector unparticles, and conclusively demonstrate that these induce Riessner–Nordström (RN)-like solutions where the role of the “charge” is defined by a composite of unparticle phase space parameters. These black holes admit double-horizon structure, although unlike the RN metric these solutions have a minimum inner horizon value. In the extremal limit, the Hawking temperature is shown to vanish. As with the scalar/tensor ...


Constraints On Vector Unparticle Physics From Cosmic Censorship, Jonas R. Mureika Sep 2017

Constraints On Vector Unparticle Physics From Cosmic Censorship, Jonas R. Mureika

Jonas Mureika

Vector unparticle couplings to standard model fields produce repulsive corrections to gravity. From a general relativistic perspective, this leads to an effective Reissner-Nordstrom-like metric whose "charge" is a function of the unparticle coupling constant λ, and therefore can admit naked singularities. Requiring the system to respect cosmic censorship provides a new method of constraining the value of λ. These limits are extremely loose for stellar-mass black holes, but commensurate with existing bounds for primordial black holes. In the case of theoretical low-mass black holes, the bounds on λ are much stricter than those derived from astrophysical and accelerator phenomenology. Additional ...


The First Open-Source General Relativistic Force-Free Electrodynamics Code, Maria Babiuc-Hamilton, Zach Etienne, Mew-Bing Wan Aug 2017

The First Open-Source General Relativistic Force-Free Electrodynamics Code, Maria Babiuc-Hamilton, Zach Etienne, Mew-Bing Wan

Maria C. Babiuc-Hamilton

We are writing the first open-source, general relativistic force-free electrodynamics code: GiRaFFE. The goal is to numerically simulate neutron star and black hole magnetospheres. The GiRaFFE is alive! It has passed a number of 1D code validation tests, and 3D tests are underway. We plan to release the code and test suite initial data routines open-source to the community.


Simulating Magnetospheres With Numerical Relativity: The Giraffe Code, Maria Babiuc-Hamilton Aug 2017

Simulating Magnetospheres With Numerical Relativity: The Giraffe Code, Maria Babiuc-Hamilton

Maria C. Babiuc-Hamilton

Numerical Relativity is successful in the simulation of black holes and gravitational waves. In recent years, teams have tackled the problem of the interaction of gravitational and electromagnetic waves. We developed a new code for the numerical simulation of neutron and black hole magnetospheres, using the FFE formalism. We tested the performance of the new code named GiRaFFE, in 1D and 3D test suits. We will study magnetospheres, focusing on jets by the Blandford -Znajek mechanism.


A Hyperbolic Solver For Black Hole Initial Data In Numerical Relativity, Maria Babiuc-Hamilton, Jeff Winicour, I. Racz Jul 2017

A Hyperbolic Solver For Black Hole Initial Data In Numerical Relativity, Maria Babiuc-Hamilton, Jeff Winicour, I. Racz

Maria C. Babiuc-Hamilton

Initial data in numerical relativity. The constraints are formulated as elliptic equations, parabolic equations and strongly hyperbolic equations. This presentation is about a different approach to initial data for black holes, the strongly hyperbolic method.