Physics Commons^™

Undergraduate Research In Gravitational Waves Astronomy At Marshall University, Maria Babiuc-Hamilton

Physics Faculty Research

This is a presentation of undergraduate student research into gravitational waves at Marshall University.

Tools For Gravitational Wave Astronomy, Maria Babiuc-Hamilton

Physics Faculty Research

Gravitational waves have been confirmed. Tools are available for their study, including the Einstein Toolkit, SimulationTools and the SXS Gravitational Waveform Database.

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

Physics Faculty Research

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.

Steps Towards A Nonlinear Cauchy-Characteristic Code Patching, Maria Babiuc-Hamilton

Physics Faculty Research

Cauchy-characteristic extractions (CCE) avoids the errors due to extraction at finite worldtube. The Cauchy and the characteristic approaches have complementary strengths and weaknesses. Unification of the two methods is a promising way of combining the strengths of both formalisms.

Gravitational & Electromagnetic Waves On The Null Cone, Maria Babiuc-Hamilton

Physics Faculty Research

Bondi (1962) proved mathematically the existence of gravitational waves at null infinity. He found an exact solution of Einstein equations. Within this metric, he calculated the loss of mass due to the emission of gravitational waves. The mas of a system is constant if and only if there is no news. If there is news, the mass decreases as long as there are news.

An Analysis Of The Gravitational Waves Null Memory, Maria Babiuc-Hamilton

Physics Faculty Research

Gravitational wave astronomy sees (hears) gravitational waves by observing the phenomena of gravitational and electromagnetic memory, and the formation of trapped surfaces and horizons.

A New Algorithm For The Numerical Computation Of Gravitational Waves, Maria Babiuc-Hamilton, Jeff Winicour

Physics Faculty Research

With gravitational waves, Gravitational Wave Astronomy can “see” colliding back holes and galaxies, the birth of a black hole in a supernova, the growth pains of our universe and the structure of spacetime.

Towards A Standardized Characteristic Extraction Tool, Maria Babiuc-Hamilton

Physics Faculty Research

Knowing the precise details of the gravitational wave signature obtained from numerical simulations of binary black hole mergers is a key requirement for meaningful detection and scientific interpretation of the data. However, the waveforms are not easy to be accurately computed. The importance of this problem to the future of gravitational wave astronomy is well recognized. Cauchy-Characteristic Extraction (CCE) is the most precise and refined extraction method available. The CCE technique connects the strong-field Cauchy evolution of the spacetime near the merger to the characteristic evolution to future null infinity where the waveform is extracted in an unambiguous way. Recently, …

Towards Improved Accuracy Of Gravitational Waves Extraction, Maria Babiuc-Hamilton

Physics Faculty Research

• Results in developing two new methods to improve the accuracy of waveform extraction using characteristic evolution.
• Numerical method: circular boundaries, with angular dissipation in the characteristic code.
• Geometric method: computation of Weyl tensor component Y₄ at null infinity, in a conformally compactified treatment.
• Comparison and calibration in tests problems based upon linearized waves.

Towards A Fully Nonlinear Cauchy Characteristic Extraction, Maria Babiuc-Hamilton

Physics Faculty Research

The artificial finite outer boundary present in Cauchy codes introduce two sources of error: The outer boundary condition and waveform extraction at an inner worldtube. The problem of proper boundary condition for a radiating system can be solved only by extension to Ι+ (conformal compactification). Cauchy Characteristic Extraction (CCE) offers a means to avoid these errors.