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Full-Text Articles in Physical Sciences and Mathematics
Properties Of Slicing Conditions For Charged Black Holes, Sean E. Li
Properties Of Slicing Conditions For Charged Black Holes, Sean E. Li
Honors Projects
We consider an earlier analysis by Baumgarte and de Oliveira (2022) of static Bona-Massó slices of stationary, nonrotating, uncharged black holes, represented by Schwarzschild spacetimes, and generalize that approach to Reissner-Nordström (RN) spacetimes, representing stationary, nonrotating black holes that carry a nonzero charge. This charge is parametrized by the charge-to-mass ratio λ ≡ Q/M, where M is the black-hole mass and the charge Q may represent electrical charge or act as a placeholder for extensions of general relativity. We use a height-function approach to construct time-independent, spherically symmetric slices that satisfy a so-called Bona-Massó slicing condition. We …
Critical Phenomena In The Gravitational Collapse Of Electromagnetic Dipole And Quadrupole Waves, Maria F. Perez Mendoza
Critical Phenomena In The Gravitational Collapse Of Electromagnetic Dipole And Quadrupole Waves, Maria F. Perez Mendoza
Honors Projects
We report on critical phenomena in the gravitational collapse of electromagnetic waves. Generalizing earlier results that focused on dipole electromagnetic waves, we here compare with quadrupole waves in axisymmetry. We perform numerical simulations of dipole and quadrupole wave initial data, fine-tuning both sets of data to the onset of black hole formation in order to study the critical solution and related critical phenomena. We observe that different multipole moments have different symmetries, indicating that the critical solution for electromagnetic waves cannot be unique, at least not globally. This is confirmed in our numerical simulations: while dipole data lead to a …
Accretion Onto Endoparasitic Black Holes At The Center Of Neutron Stars, Chloe B. Richards
Accretion Onto Endoparasitic Black Holes At The Center Of Neutron Stars, Chloe B. Richards
Honors Projects
We revisit the system consisting of a neutron star that harbors a small, possibly primordial, black hole at its center, focusing on a nonspinning black hole embedded in a nonrotating neutron star. Extending earlier treatments, we provide an analytical treatment describing the rate of secular accretion of the neutron star matter onto the black hole, adopting the relativistic Bondi accretion formalism for stiff equations of state that we presented elsewhere. We use these accretion rates to sketch the evolution of the system analytically until the neutron star is completely consumed. We also perform numerical simulations in full general relativity for …
Bondi Accretion In Trumpet Geometries, August J. Miller
Bondi Accretion In Trumpet Geometries, August J. Miller
Honors Projects
The Bondi solution, which describes the radial inflow of a gas onto a non-rotating black hole, provides a powerful test for numerical relativistic codes. However, this solution is typically derived in Schwarzschild coordinates, which are not well suited for dynamical spacetime evolutions. Instead, many current numerical relativistic codes adopt moving-puncture coordinates, which render black holes in trumpet geometries. Here we transform the Bondi solution into two different trumpet coordinate systems, both of which result in regular expressions for the fluid flow extending into the black hole interior. We also evolve these solutions numerically and demonstrate their usefulness for testing and …