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Full-Text Articles in Physical Sciences and Mathematics

Detection And Inference In Gravitational Wave Astronomy, Steven Daniel Reyes Dec 2019

Detection And Inference In Gravitational Wave Astronomy, Steven Daniel Reyes

Dissertations - ALL

We explore the detection and astrophysical modeling of gravitational waves de- tected by the Advanced Laser Interferometer Gravitational wave Observatory (LIGO) and Virgo. We discuss the techniques used in the PyCBC search pipeline to discover the first gravitational wave detection GW150914, and estimate the statistical signifi- cance of GW150914, and the marginal trigger LVT151012. During Advanced LIGO’s first observing run there were no detections of mergers from binary neutron star and neutron star-black hole binaries. We use Bayesian inference to place upper limits on the rate of coalescence of these binaries. We use developments made in the PyCBC search pipeline …


The Astrophysics Of Nanohertz Gravitational Waves, S. Burke-Spolaor, S. R. Taylor, M. Charisi, T. Dolch, J. S. Hazboun, A. M. Holgado, L. Z. Kelley, T. J. W. Lazio, D. R. Madison, N. Mcmann, C. M. F. Mingarelli, A. Rasskazov, X. Siemens, J. J. Simon, Tristan L. Smith Dec 2019

The Astrophysics Of Nanohertz Gravitational Waves, S. Burke-Spolaor, S. R. Taylor, M. Charisi, T. Dolch, J. S. Hazboun, A. M. Holgado, L. Z. Kelley, T. J. W. Lazio, D. R. Madison, N. Mcmann, C. M. F. Mingarelli, A. Rasskazov, X. Siemens, J. J. Simon, Tristan L. Smith

Physics & Astronomy Faculty Works

Pulsar timing array (PTA) collaborations in North America, Australia, and Europe, have been exploiting the exquisite timing precision of millisecond pulsars over decades of observations to search for correlated timing deviations induced by gravitational waves (GWs). PTAs are sensitive to the frequency band ranging just below 1 nanohertz to a few tens of microhertz. The discovery space of this band is potentially rich with populations of inspiraling supermassive black hole binaries, decaying cosmic string networks, relic post-inflation GWs, and even non-GW imprints of axionic dark matter. This article aims to provide an understanding of the exciting open science questions in …


High Power And Optomechanics In Advanced Ligo Detectors, Terra Christine Hardwick Nov 2019

High Power And Optomechanics In Advanced Ligo Detectors, Terra Christine Hardwick

LSU Doctoral Dissertations

In September 2015, a new era of astronomy began with the first direct detection of grav- itational waves from a binary black hole coalescence. The event was captured by the Laser Interferometer Gravitational-wave Observatory, comprised of two long-baseline interferometers, one in Livingston, LA and one in Hanford, WA. At the time of the first detection, the interferometers were part way through an upgrade to an advanced configuration and were operating with a strain sensitivity of just better than 10−23/Hz1/2 around 100Hz. The full Advanced LIGO design calls for sensitivity of a few parts in 10−24/Hz …


Hasasia: A Python Package For Pulsar Timing Array Sensitivity Curves, J. S. Hazboun, J. D. Romano, Tristan L. Smith Oct 2019

Hasasia: A Python Package For Pulsar Timing Array Sensitivity Curves, J. S. Hazboun, J. D. Romano, Tristan L. Smith

Physics & Astronomy Faculty Works

No abstract provided.


Binary Black Hole Population Properties Inferred From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, B. P. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, D. Tuyenbayev, W. H. Wang, Adam Zadrozny Sep 2019

Binary Black Hole Population Properties Inferred From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, B. P. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, D. Tuyenbayev, W. H. Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

We present results on the mass, spin, and redshift distributions with phenomenological population models using the 10 binary black hole (BBH) mergers detected in the first and second observing runs completed by Advanced LIGO and Advanced Virgo. We constrain properties of the BBH mass spectrum using models with a range of parameterizations of the BBH mass and spin distributions. We find that the mass distribution of the more massive BH in such binaries is well approximated by models with no more than 1% of BHs more massive than 45M(circle dot) and a power-law index of alpha = 1.3(-1.7)(+1.4) (90% credibility). …


Dynamical Compact Objects In Numerical Relativity, Hyun Lim Aug 2019

Dynamical Compact Objects In Numerical Relativity, Hyun Lim

Theses and Dissertations

The work of this dissertation will study various aspects of the dynamics of compact objects using numerical simulations.We consider BH dynamics within two modified or alternative theories of gravity. Within a family of Einstein-Maxwell-Dilaton-Axion theories, we find that the GW waveforms from binary black hole (BBH) mergers differ from the standard GW waveform prediction of GR for especially large axion values. For more astrophysically realistic (i.e. smaller) values, the differences become negligible and undetectable. Weestablish the existence of a well-posed initial value problem for a second alternative theory fo gravity (quadratic gravity) and demonstrate in spherical symmetry that a linear …


The Delay Time Of Gravitational Wave — Gamma-Ray Burst Associations, Bing Zhang Jul 2019

The Delay Time Of Gravitational Wave — Gamma-Ray Burst Associations, Bing Zhang

Physics & Astronomy Faculty Research

The first gravitational wave (GW) — gamma-ray burst (GRB) association, GW170817/GRB 170817A, had an offset in time, with the GRB trigger time delayed by ∼1.7 s with respect to the merger time of the GW signal. We generally discuss the astrophysical origin of the delay time, Δt, of GW-GRB associations within the context of compact binary coalescence (CBC) — short GRB (sGRB) associations and GW burst — long GRB (lGRB) associations. In general, the delay time should include three terms, the time to launch a clean (relativistic) jet, Δtjet; the time for the jet to break out from the surrounding …


Towards Probing The Strong Field Gravity Using Binary Black-Hole Ringdowns, Swetha Bhagwat May 2019

Towards Probing The Strong Field Gravity Using Binary Black-Hole Ringdowns, Swetha Bhagwat

Dissertations - ALL

In this thesis, we study black hole ringdowns as a probe to understand the strong-field clssical gravity. When two black holes merge, they form a single distorted black hole that then radiates gravitational waves and settles into a final stable Kerr state. The signal produced during this process is called the ringdown and can be modelled as perturbations on the space-time of the final Kerr black hole. Ringdowns contain information about the strong field dynamics close to the black holes and thus, can be used to test our understanding of gravity. There are three specific questions that we explore in …


Searches For Continuous Gravitational Waves From 15 Supernova Remnants And Fomalhaut B With Advanced Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, Tiffany Z. Summerscales Apr 2019

Searches For Continuous Gravitational Waves From 15 Supernova Remnants And Fomalhaut B With Advanced Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, Tiffany Z. Summerscales

Faculty Publications

© 2019. The American Astronomical Society. All rights reserved. We describe directed searches for continuous gravitational waves (GWs) from 16 well-localized candidate neutron stars, assuming none of the stars has a binary companion. The searches were directed toward 15 supernova remnants and Fomalhaut b, a directly imaged extrasolar planet candidate that has been suggested to be a nearby old neutron star. Each search covered a broad band of frequencies and first and second time derivatives. After coherently integrating spans of data from the first Advanced LIGO observing run of 3.5-53.7 days per search, applying data-based vetoes, and discounting known instrumental …


Low-Latency Gravitational-Wave Alerts For Multimessenger Astronomy During The Second Advanced Ligo And Virgo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Apr 2019

Low-Latency Gravitational-Wave Alerts For Multimessenger Astronomy During The Second Advanced Ligo And Virgo Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Advanced LIGO's second observing run (O2), conducted from 2016 November 30 to 2017 August 25, combined with Advanced Virgo's first observations in 2017 August, witnessed the birth of gravitational-wave multimessenger astronomy. The first ever gravitational-wave detection from the coalescence of two neutron stars, GW170817, and its gamma-ray counterpart, GRB 170817A, led to an electromagnetic follow-up of the event at an unprecedented scale. Several teams from across the world searched for EM/neutrino counterparts to GW170817, paving the way for the discovery of optical, X-ray, and radio counterparts. In this article, we describe the online identification of gravitational-wave transients and the distribution …


Charged Compact Binary Coalescence Signal And Electromagnetic Counterpart Of Plunging Black Hole–Neutron Star Mergers, Bing Zhang Mar 2019

Charged Compact Binary Coalescence Signal And Electromagnetic Counterpart Of Plunging Black Hole–Neutron Star Mergers, Bing Zhang

Physics & Astronomy Faculty Research

If at least one of the members of a compact binary coalescence is charged, the inspiral of the two members would generate a Poynting flux with an increasing power, giving rise to a brief electromagnetic counterpart temporally associated with the chirp signal of the merger (with possibly a small temporal offset), which we term as the charged compact binary coalescence (cCBC) signal. We develop a general theory of cCBC for any mass and amount of charge for each member. Neutron stars (NSs), as spinning magnets, are guaranteed to be charged, so the cCBC signal should accompany all NS mergers. The …


Ligo Analogy Lab—A Set Of Undergraduate Lab Experiments To Demonstrate Some Principles Of Gravitational Wave Detection, Dennis Ugolini, Hanna Rafferty, M. Winter, C. Rockstuhl, A. Bergmann Jan 2019

Ligo Analogy Lab—A Set Of Undergraduate Lab Experiments To Demonstrate Some Principles Of Gravitational Wave Detection, Dennis Ugolini, Hanna Rafferty, M. Winter, C. Rockstuhl, A. Bergmann

Physics and Astronomy Faculty Research

The first direct detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in September 2015 proved their existence, as predicted by Einstein's General Theory of Relativity, and ushered in the era of gravitational-wave interferometry. In this article, we present a set of lab course experiments at different levels of advancement, which give students insight into the basic LIGO operating principle and advanced detection techniques. Starting with methods for folding an optical cavity, we advance to analogy experiments with sound waves that can be detected with a Michelson interferometer with an optical cavity arm. In that experiment, students also …


Various Paths To The Spontaneous Growth Of $P$-Form Fields, Fethi̇ Mübi̇n Ramazanoğlu Jan 2019

Various Paths To The Spontaneous Growth Of $P$-Form Fields, Fethi̇ Mübi̇n Ramazanoğlu

Turkish Journal of Physics

We show that $p$-form fields can go through spontaneous growth due to various couplings in gravity theories, forming a new example of spontaneous tensorization. Generalizing the spontaneous scalarization theory of Damour and Esposito-Farèse where the original idea has been applied to different fields from vectors to spinors has received high levels of interest in recent years. We first review this existing literature on spontaneous growth in gravity, and then apply the known mechanisms to $p$-forms. We show that one can induce spontaneous growth in $p$-forms for each of the regularized instability mechanisms, which was not the case for other types …


Gravitational Radiation From Superradiant Instabilities Of Rotating Black Holes, Shrobana Ghosh Jan 2019

Gravitational Radiation From Superradiant Instabilities Of Rotating Black Holes, Shrobana Ghosh

Electronic Theses and Dissertations

We use the Teukolsky formalism to calculate the gravitational radiation from a non-axi\-symmetric cloud formed due to superradiant amplification of a spin-0 bosonic field. We focus on the prospects of the future space-based gravitational wave detector, Laser Interferometer Space Antenna (LISA), and the current version of ground-based detector, Advanced Laser Interferometer Gravitational-Wave Observatory (AdLIGO), to detect or constrain scalars with mass in the range $m_s\in [10^{-19},10^{-15}]$ eV and $m_s\in[10^{-14},10^{-11}]$ eV, respectively. Using astrophysical models of black hole populations calibrated to observations we find that, in optimistic scenarios, AdLIGO could detect up to $10^4$ resolvable events in a four-year search if …


Calculating Water Wavelength Using Dispersion Relation And Approximation, Chantelle Lee Jan 2019

Calculating Water Wavelength Using Dispersion Relation And Approximation, Chantelle Lee

Undergraduate Journal of Mathematical Modeling: One + Two

The dispersion relation equation is used to directly compute wave number and wave length to compliment water wave pressure sensor readings. Waves are measured to help coastal engineering to better mitigate coastal infrastructures. Various given wave periods and water depths are used to show how the dispersion relation equation could compute wave length. Also, shallow and deep-water approximations are formulated from the dispersion relation equation and the results are compared.


Search For Multimessenger Sources Of Gravitational Waves And High-Energy Neutrinos With Advanced Ligo During Its First Observing Run, Antares, And Icecube, A. Albert, M. André, M. Anghinolfi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Jan 2019

Search For Multimessenger Sources Of Gravitational Waves And High-Energy Neutrinos With Advanced Ligo During Its First Observing Run, Antares, And Icecube, A. Albert, M. André, M. Anghinolfi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Astrophysical sources of gravitational waves, such as binary neutron star and black hole mergers or core-collapse supernovae, can drive relativistic outflows, giving rise to non-thermal high-energy emission. High-energy neutrinos are signatures of such outflows. The detection of gravitational waves and high-energy neutrinos from common sources could help establish the connection between the dynamics of the progenitor and the properties of the outflow. We searched for associated emission of gravitational waves and high-energy neutrinos from astrophysical transients with minimal assumptions using data from Advanced LIGO from its first observing run O1, and data from the Antares and IceCube neutrino observatories from …


A Fermi Gamma-Ray Burst Monitor Search For Electromagnetic Signals Coincident With Gravitational-Wave Candidates In Advanced Ligo's First Observing Run, E. Burns, A. Goldstein, C. M. Hui, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Jan 2019

A Fermi Gamma-Ray Burst Monitor Search For Electromagnetic Signals Coincident With Gravitational-Wave Candidates In Advanced Ligo's First Observing Run, E. Burns, A. Goldstein, C. M. Hui, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present a search for prompt gamma-ray counterparts to compact binary coalescence gravitational wave (GW) candidates from Advanced LIGO's first observing run (O1). As demonstrated by the multimessenger observations of GW170817/GRB 170817A, electromagnetic and GW observations provide complementary information about the astrophysical source, and in the case of weaker candidates, may strengthen the case for an astrophysical origin. Here we investigate low-significance GW candidates from the O1 compact binary coalescence searches using the Fermi Gamma-Ray Burst Monitor (GBM), leveraging its all sky and broad energy coverage. Candidates are ranked and compared to background to measure the significance. Those with false …