Open Access. Powered by Scholars. Published by Universities.^{®}
 Institution

 University of Kentucky (503)
 Brigham Young University (174)
 University of Texas Rio Grande Valley (157)
 Iowa State University (64)
 San Jose State University (58)

 Old Dominion University (49)
 Utah State University (34)
 University of Tennessee, Knoxville (33)
 Dartmouth College (29)
 Valparaiso University (27)
 Western University (23)
 West Virginia University (22)
 The University of San Francisco (21)
 Bowling Green State University (17)
 Wright State University (16)
 EmbryRiddle Aeronautical University (15)
 California Polytechnic State University, San Luis Obispo (14)
 University of Missouri, St. Louis (14)
 Georgia State University (13)
 Western Kentucky University (12)
 Kennesaw State University (11)
 Georgia Southern University (10)
 Technological University Dublin (8)
 University of New Orleans (8)
 University of Richmond (6)
 University of Nevada, Las Vegas (5)
 University of Pennsylvania (4)
 University of Nebraska  Lincoln (4)
 Chapman University (4)
 College of Saint Benedict and Saint John's University (3)
 Keyword

 Galaxies (62)
 ISM (31)
 Publications (30)
 Quasars (29)
 Atomic data (27)

 Active galaxies (27)
 Evolution (26)
 Galaxy evolution (26)
 Atomic processes (22)
 Physics and Astronomy (20)
 Galaxies: Seyfert (20)
 Highredshift (20)
 Galaxies: Active (20)
 Extinction (20)
 Scattering (20)
 Plasmas (19)
 Astronomy (18)
 Stars (16)
 Radiative Transfer (16)
 Physics (16)
 Collisions (15)
 Cosmology (15)
 Galaxies: active (15)
 H II regions (15)
 Surveys (14)
 Galaxy formation (14)
 Structure (13)
 ISM: Dust (13)
 CD (13)
 Emission Spectra (13)
 Publication

 Physics and Astronomy Faculty Publications (530)
 Faculty Publications (247)
 Physics and Astronomy Faculty Publications and Presentations (157)
 Physics Faculty Publications (87)
 Physics and Astronomy Publications (76)

 Cross Sections (32)
 Open Dartmouth: Published works by Dartmouth faculty (29)
 Faculty & Staff Scholarship (22)
 Symposium on Undergraduate Research and Creative Expression (SOURCE) (21)
 Physics and Astronomy (21)
 All Physics Faculty Publications (18)
 Publications (18)
 Physics and Astronomy Faculty Patents (15)
 STAR (STEM Teacher and Researcher) Presentations (14)
 UMSL Faculty Works (14)
 Articles (8)
 Masters Theses & Specialist Projects (7)
 Chemistry Publications (7)
 Physics and Astronomy Faculty Presentations (4)
 Mathematics, Physics, and Computer Science Faculty Articles and Research (4)
 Physics: Faculty Publications and Other Works (3)
 Department of Physics Papers (3)
 Physics & Astronomy Faculty Publications (3)
 Browse All Undergraduate research (3)
 Physics & Astronomy Faculty Works (3)
 WKU Archives Collection Inventories (3)
 IMSA Great Minds Program ® (2)
 Mathematics and Statistics Faculty and Staff Publications (2)
 Honors College (2)
 Geological and Atmospheric Sciences Publications (2)
 File Type
Articles 1  30 of 1409
FullText Articles in Physics
Using Saoimage Ds9 & Hubble Space Telescope Data To Identify Globular Clusters In Ic 219, Emily Spicer, Alice Jacques, Benne Holwerda
Using Saoimage Ds9 & Hubble Space Telescope Data To Identify Globular Clusters In Ic 219, Emily Spicer, Alice Jacques, Benne Holwerda
Undergraduate Research Events
Globular clusters are tightly bound spherical clusters of stars located within the halo of elliptical and spiral galaxies. They are among the oldest stars found in a galaxy, and their presence and abundance in a galaxy’s halo offer insight on the age, composition, and formation of the galaxy.1 I used a Hubble Space Telescope (HST) image and SAOImage DS9, a powerful imaging tool used to analyze astronomical data, to identify the size and locate the position of globular cluster (GC) candidates in IC 219.
Optical Study Of Pks B1322110, The IntraHour Variable Radio Source, Juan P. Madrid, Artem V. Tuntsov, Mischa Schirmer, Mark A. Walker, Carlos J. Donzelli, Keith W. Bannister, Hayley E. Bignall, Jamie Stevens, Cormac Reynolds, Simon Johnston
Optical Study Of Pks B1322110, The IntraHour Variable Radio Source, Juan P. Madrid, Artem V. Tuntsov, Mischa Schirmer, Mark A. Walker, Carlos J. Donzelli, Keith W. Bannister, Hayley E. Bignall, Jamie Stevens, Cormac Reynolds, Simon Johnston
Physics and Astronomy Faculty Publications and Presentations
Observations with the Australia Telescope Compact Array revealed intrahour variations in the radio source PKS B1322110 (Bignall et al. 2019). As part of an optical followup, we obtained Gemini Hα and Hα continuum (HαC) images of the PKS B1322110 field. A robust 19 σ detection of PKS B1322 110 in the Hα−HαC image prompted us to obtain the first optical spectrum of PKS B1322110. With the Gemini spectrum we determine that PKS B1322110 is a flatspectrum radio quasar at a redshift of z = 3.007 ± 0.002. The apparent flux detected in the Hα filter is likely to originate ...
Sensitivity And Performance Of The Advanced Ligo Detectors In The Third Observing Run, A. Buikema, C. Cahillane, G. L. Mansell, C. D. Blair, R. Abbott, C. Adamsn, R. Adhikari, K. E. Ramirez
Sensitivity And Performance Of The Advanced Ligo Detectors In The Third Observing Run, A. Buikema, C. Cahillane, G. L. Mansell, C. D. Blair, R. Abbott, C. Adamsn, R. Adhikari, K. E. Ramirez
Physics and Astronomy Faculty Publications and Presentations
On April 1st, 2019, the Advanced Laser Interferometer GravitationalWave Observatory (aLIGO), joined by the Advanced Virgo detector, began the third observing run, a yearlong dedicated search for gravitational radiation. The LIGO detectors have achieved a higher duty cycle and greater sensitivity to gravitational waves than ever before, with LIGO Hanford achieving angleaveraged sensitivity to binary neutron star coalescences to a distance of 111 Mpc, and LIGO Livingston to 134 Mpc with duty factors of 74.6% and 77.0% respectively. The improvement in sensitivity and stability is a result of several upgrades to the detectors, including doubled intracavity power, the ...
26 Results Of Hyperbolic Partial Differential Equations In BPoly Basis, Muhammad I. Bhatti, Emilio Hinojosa
26 Results Of Hyperbolic Partial Differential Equations In BPoly Basis, Muhammad I. Bhatti, Emilio Hinojosa
Physics and Astronomy Faculty Publications and Presentations
A twovariable process to estimate results of Hyperbolic Partial Differentiation (HPD) equations in a BPolynomial (BPoly) bases is established. In the proposed process, a linear product of variable coefficients and BPolys is manipulated to express the predicted solution of the HPD equation. The variable coefficients of the linear mixture in the results are concluded using Galerkin technique. The HPD equation is converted into a matrix which when inverted provided the unknown coefficients in the linear mixture of the solution. The anticipated solution is constructed from the variable coefficients and BPoly basis set as a product with initial conditions implemented. Both ...
Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M⊙, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny
Gw190521: A Binary Black Hole Merger With A Total Mass Of 150 M⊙, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny
Physics and Astronomy Faculty Publications and Presentations
On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitationalwave signal, GW190521, with a threedetector network signaltonoise ratio of 14.7, and an estimated falsealarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85+21−14 M⊙ and 66+17−18 M⊙ (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pairinstability supernova ...
Properties And Astrophysical Implications Of The 150 M ⊙ Binary Black Hole Merger Gw190521, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, S. Mukherjee, V. Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny
Properties And Astrophysical Implications Of The 150 M ⊙ Binary Black Hole Merger Gw190521, R. Abbott, T. D. Abbott, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, S. Mukherjee, V. Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, A. K. Zadrozny
Physics and Astronomy Faculty Publications and Presentations
The gravitationalwave signal GW190521 is consistent with a binary black hole (BBH) merger source at redshift 0.8 with unusually high component masses, M ⊙ and M ⊙, compared to previously reported events, and shows mild evidence for spininduced orbital precession. The primary falls in the mass gap predicted by (pulsational) pairinstability supernova theory, in the approximate range 65–120 M ⊙. The probability that at least one of the black holes in GW190521 is in that range is 99.0%. The final mass of the merger ( M ⊙) classifies it as an intermediatemass black hole. Under the assumption of a quasicircular BBH coalescence ...
Modifications To Gravitational Wave Equation From Canonical Quantum Gravity, Andrea Dapor, Klaus Liegener
Modifications To Gravitational Wave Equation From Canonical Quantum Gravity, Andrea Dapor, Klaus Liegener
Faculty Publications
It is expected that the quantum nature of spacetime leaves its imprint in all semiclassical gravitational systems, at least in certain regimes, including gravitational waves. In this paper we investigate such imprints on gravitational waves within a specific framework: space is assumed to be discrete (in the form of a regular cubic lattice), and this discrete geometry is quantised following Dirac's canonical quantisation scheme. The semiclassical behavior is then extracted by promoting the expectation value of the Hamiltonian operator on a semiclassical state to an effective Hamiltonian. Considering a family of semiclassical states representing small tensor perturbations to Minkowski ...
Adaptive Spline Fitting With Particle Swarm Optimization, Soumya Mohanty, Ethan Fahnestock
Adaptive Spline Fitting With Particle Swarm Optimization, Soumya Mohanty, Ethan Fahnestock
Physics and Astronomy Faculty Publications and Presentations
In fitting data with a spline, finding the optimal placement of knots can significantly improve the quality of the fit. However, the challenging highdimensional and nonconvex optimization problem associated with completely free knot placement has been a major roadblock in using this approach. We present a method that uses particle swarm optimization (PSO) combined with model selection to address this challenge. The problem of overfitting due to knot clustering that accompanies free knot placement is mitigated in this method by explicit regularization, resulting in a significantly improved performance on highly noisy data. The principal design choices available in the method ...
Diffuse Spectra Model Of Photoluminescence In Carbon Quantum Dots, S. E. Kumekov, N. K. Saitova, Karen S. Martirosyan
Diffuse Spectra Model Of Photoluminescence In Carbon Quantum Dots, S. E. Kumekov, N. K. Saitova, Karen S. Martirosyan
Physics and Astronomy Faculty Publications and Presentations
The attractive aspect of excitation related to fluorescence nature in carbon quantum dots (CQD) has guided to several assumptions correlated with clusters size distribution, shapes as well as presence of different emissive states. In this study, a dimer–excimer model of photoluminescence (PL) in CQD describing discrete multiple electronic states for the excitationdependent emission is described. The functional dependence of the characteristic width of the diffuse spectra of PL on the size of a quantum dots are calculated. The effective width of PL spectrum can be tuned from 0.1 to 1 eV.
Absence Of LandauPeierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera
Absence Of LandauPeierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera
Physics and Astronomy Faculty Publications and Presentations
We investigate the stability of the magnetic dual chiral density wave (MDCDW) phase of cold and dense QCD against collective lowenergy fluctuations of the order parameter. The appearance of additional structures in the system free energy due to the explicit breaking of the rotational and isospin symmetries by the external magnetic field play a crucial role in the analysis. The new structures stiffen the spectrum of the thermal fluctuations in the transverse direction, thereby avoiding the LandauPeierls instability that affects singlemodulated phases at arbitrarily low temperatures. The lack of LandauPeierls instabilities in the MDCDW phase makes this inhomogeneous phase of ...
Absence Of LandauPeierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera
Absence Of LandauPeierls Instability In The Magnetic Dual Chiral Density Wave Phase Of Dense Qcd, Efrain J. Ferrer, Vivian De La Incera
Physics and Astronomy Faculty Publications and Presentations
We investigate the stability of the magnetic dual chiral density wave (MDCDW) phase of cold and dense QCD against collective lowenergy fluctuations of the order parameter. The appearance of additional structures in the system free energy due to the explicit breaking of the rotational and isospin symmetries by the external magnetic field play a crucial role in the analysis. The new structures stiffen the spectrum of the thermal fluctuations in the transverse direction, thereby avoiding the LandauPeierls instability that affects singlemodulated phases at arbitrarily low temperatures. The lack of LandauPeierls instabilities in the MDCDW phase makes this inhomogeneous phase of ...
Astroalign: A Python Module For Astronomical Image Registration, Martin Beroiz, Juan B. Cabral, Bruno Sanchez
Astroalign: A Python Module For Astronomical Image Registration, Martin Beroiz, Juan B. Cabral, Bruno Sanchez
Physics and Astronomy Faculty Publications and Presentations
We present an algorithm implemented in the Astroalign Python module for image registration in astronomy. Our module does not rely on WCS information and instead matches threepoint asterisms (triangles) on the images to find the most accurate linear transformation between them. It is especially useful in the context of aligning images prior to stacking or performing difference image analysis. Astroalign can match images of different pointspread functions, seeing, and atmospheric conditions.
Towards Realism Interpretation Of Wave Mechanics Based On Maxwell Equations In Quaternion Space And Some Implications, Including Smarandache’S Hypothesis, Florentin Smarandache, Victor Christianto, Yunita Umniyati
Towards Realism Interpretation Of Wave Mechanics Based On Maxwell Equations In Quaternion Space And Some Implications, Including Smarandache’S Hypothesis, Florentin Smarandache, Victor Christianto, Yunita Umniyati
Mathematics and Statistics Faculty and Staff Publications
No abstract provided.
Physics 516: Electromagnetic Phenomena (Spring 2020), Philip C. Nelson
Physics 516: Electromagnetic Phenomena (Spring 2020), Philip C. Nelson
Department of Physics Papers
These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether or not you find errors: pcn@upenn.edu.
Design And Construction Of A Computer Controlled Astronomical Spectropolarimeter, Jacob Marchio
Design And Construction Of A Computer Controlled Astronomical Spectropolarimeter, Jacob Marchio
Honors College
A theoretical description of a simple optical train, modulated signal based spectropolarimeter is discussed. The design includes, after the telescope optical tube (in this case, a 9.25” Schmidt Cassegrain), a rotating quarter waveplate (compensator), a fixed linear polarizer (analyzer), and transmission grating of 100l/mm, with a ZWO ASI290mm astronomical camera. The practical constraints on implementing such an instrument are discussed, and the construction of the spectropolarimeter is detailed, including the necessary optics, optomechanics, and electromechanics. The rotation and recording of the rotating compensator is facilitated by a motorized connection with proportional feedback control, and the uncertainty in measuring ...
Investigating The Stability Of Observed Low SemiMajor Axis Exoplanetary Systems With Hypothetical Outer Planets Using The Program Mercury6, Kendall Butler
Investigating The Stability Of Observed Low SemiMajor Axis Exoplanetary Systems With Hypothetical Outer Planets Using The Program Mercury6, Kendall Butler
Honors College
This project investigates the stability of observed planetary systems, and whether this stability remains in the presence of additional outer planets. This made use of the program Mercury6, an nbody integrator that computes the changes in planetary orbits over time. The Systems HD 136352, GJ 9827, and HD 7924 were studied with initial conditions taken from the available observational data. This information was curated using the online NASA Exoplanet archive of confirmed exoplanets. With these initial conditions, Mercury6 computed the changing planetary orbits of each system for 5 million years. For each of these systems, a single outer planet, which ...
Fingerprints Of Binary Black Hole Formation Channels Encoded In The Mass And Spin Of Merger Remnants, Manuel Arca Sedda, Michaela Mapelli, Mario Spera, Matthew Benacquista, Nicola Giacobbo
Fingerprints Of Binary Black Hole Formation Channels Encoded In The Mass And Spin Of Merger Remnants, Manuel Arca Sedda, Michaela Mapelli, Mario Spera, Matthew Benacquista, Nicola Giacobbo
Physics and Astronomy Faculty Publications and Presentations
Binary black holes (BBHs) are thought to form in different environments, including the galactic field and (globular, nuclear, young, and open) star clusters. Here, we propose a method to estimate the fingerprints of the main BBH formation channels associated with these different environments. We show that the metallicity distribution of galaxies in the local universe along with the relative amount of mergers forming in the field or in star clusters determine the main properties of the BBH population. Our fiducial model predicts that the heaviest merger to date, GW170729, originated from a progenitor that underwent 2–3 merger events in ...
An Analysis Of The Debate Over Creation, Evolution, And The Timeline Of The Universe At An Ecumenical Christian University, Mason Pohlman
An Analysis Of The Debate Over Creation, Evolution, And The Timeline Of The Universe At An Ecumenical Christian University, Mason Pohlman
Honors Theses
Throughout a significant portion of history and within modern culture, the fields of science and religion appear to be competing for the same holds in a person’s belief system. Universities are where academics and the sciences are the prevailing held truth, while in churches, the Bible reigns as supreme authority. However, in a Christian academic setting, the predominate school of thought in belief systems might turn into a little more of a melting pot. By analyzing gathered personal data (via surveys and interviews), one can begin to piece together the predominate thoughts on the apparent conflict between religion and ...
Towards A RealTime FullyCoherent AllSky Search For Gravitational Waves From Compact Binary Coalescences Using Particle Swarm Optimization, M. E. Normandin, Soumya Mohanty
Towards A RealTime FullyCoherent AllSky Search For Gravitational Waves From Compact Binary Coalescences Using Particle Swarm Optimization, M. E. Normandin, Soumya Mohanty
Physics and Astronomy Faculty Publications and Presentations
While a fullycoherent allsky search is known to be optimal for detecting gravitational wave signals from compact binary coalescences, its high computational cost has limited current searches to less sensitive coincidencebased schemes. Following up on previous work that has demonstrated the effectiveness of particle swarm optimization (PSO) in reducing the computational cost of this search, we present an implementation that achieves near realtime computational speed. This is achieved by combining the search efficiency of PSO with a significantly revised and optimized numerical implementation of the underlying mathematical formalism along with additional multithreaded parallelization layers in a distributed computing framework. For ...
Toros Optical FollowUp Of The Advanced Ligo–Virgo O2 Second Observational Campaign, Rodolfo Artola, Martin Beroiz, Juan Cabral, R. Camuccio, Moises Castillo, Mario C. Diaz, Aldo Fonrouge, Alejandro F. Hinojosa, Andrea Hinojosa, Americo F. Hinojosa, Wendy Mendoza, Victor Perez, Tania Penuela, Wahltyn Rattray, Ervin Vilchis, Adam Zadrozny
Toros Optical FollowUp Of The Advanced Ligo–Virgo O2 Second Observational Campaign, Rodolfo Artola, Martin Beroiz, Juan Cabral, R. Camuccio, Moises Castillo, Mario C. Diaz, Aldo Fonrouge, Alejandro F. Hinojosa, Andrea Hinojosa, Americo F. Hinojosa, Wendy Mendoza, Victor Perez, Tania Penuela, Wahltyn Rattray, Ervin Vilchis, Adam Zadrozny
Physics and Astronomy Faculty Publications and Presentations
We present themethods and results of the optical followup, conducted by the Transient Optical Robotic Observatory of the South Collaboration, of gravitational wave events detected during the Advanced LIGO–Virgo second observing run (2016 November–2017 August). Given the limited field of view (∼100 arcmin) of our observational instrumentation, we targeted galaxies within the area of high localization probability that were observable from our sites. We analysed the observations using difference imaging, followed by a random forest algorithm to discriminate between real and spurious transients. Our observations were conducted using telescopes at Estacion Astrofısica de Bosque Alegre, Cerro Tololo InterAmerican ...
LoopClosure Kinetics Reveal A Stable, RightHanded Dna Intermediate In Cre Recombination, Massa J. Shoura, Stefan M. Giovan, Alexandre A. Vetcher, Riccardo Ziraldo, Andreas Hanke, Stephen D. Levene
LoopClosure Kinetics Reveal A Stable, RightHanded Dna Intermediate In Cre Recombination, Massa J. Shoura, Stefan M. Giovan, Alexandre A. Vetcher, Riccardo Ziraldo, Andreas Hanke, Stephen D. Levene
Physics and Astronomy Faculty Publications and Presentations
In Cre sitespecific recombination, the synaptic intermediate is a recombinase homotetramer containing a pair of loxP DNA target sites. The enzyme system's strandexchange mechanism proceeds via a Hollidayjunction (HJ) intermediate; however, the geometry of DNA segments in the synapse has remained highly controversial. In particular, all crystallographic structures are consistent with an achiral, planar Hollidayjunction (HJ) structure, whereas topological assays based on Cremediated knotting of plasmid DNAs are consistent with a righthanded chiral junction. We use the kinetics of loop closure involving closely spaced (131–151 bp) loxP sites to investigate the inaqueo ensemble of conformations for the longestlived ...
Lack Of Debye And Meissner Screening In Strongly Magnetized Quark Matter At Intermediate Densities, Bo Feng, Efrain J. Ferrer, Israel Portillo
Lack Of Debye And Meissner Screening In Strongly Magnetized Quark Matter At Intermediate Densities, Bo Feng, Efrain J. Ferrer, Israel Portillo
Physics and Astronomy Faculty Publications and Presentations
We study the static responses of cold quark matter in the intermediate baryonic density region (characterized by a chemical potential μ) in the presence of a strongmagnetic field. We consider in particular, the socalled magnetic dual Chiral Density Wave (MDCDW) phase, which is materialized by an inhomogeneous condensate formed by a particlehole pair. It is shown, that the MDCDW phase is more stable in the weakcoupling regime than the one considered in the magnetic catalysis of chiral symmetry braking phenomenon and even than the chiral symmetric phase that was expected to be realized at sufficiently high baryonic chemical potential. The ...
Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, ErnstAlbrecht Zwicknagel
Expectation Values Of Coherent States For Su(2) Lattice Gauge Theories, Klaus Liegener, ErnstAlbrecht Zwicknagel
Faculty Publications
This article investigates properties of semiclassical Gauge Field Theory Coherent States for general quantum gauge theories. Useful, e.g., for the canonical formulation of Lattice Gauge Theories these states are labelled by a point in the classical phase space and constructed such that the expectation values of the canonical operators are sharply peaked on said phase space point. For the case of the nonabelian gauge group SU(2), we will explicitly compute the expectation value of general polynomials including the first order quantum corrections. This allows asking more precise questions about the quantum fluctuations of any given semiclassical system.
Simulating The Outer Layers Of Rapidly Rotating Stars, Frank J. Robinson, Joel Tanner, Sarbani Basu
Simulating The Outer Layers Of Rapidly Rotating Stars, Frank J. Robinson, Joel Tanner, Sarbani Basu
Chemistry & Physics Faculty Publications
This paper presents the results of a set of radiative hydrodynamic (RHD) simulations of convection in the nearsurface regions of a rapidly rotating star. The simulations use microphysics consistent with stellar models, and include the effects of realistic convection and radiative transfer. We find that the overall effect of rotation is to reduce the strength of turbulence. The combination of rotation and radiative cooling creates a zonal velocity profile in which the motion of fluid parcels near the surface is independent of rotation. Their motion is controlled by the strong up and down flows generated by radiative cooling. The fluid ...
A Joint FermiGbm And Ligo/Virgo Analysis Of Compact Binary Mergers From The First And Second GravitationalWave Observing Runs, R. Hamburg, C. Fletcher, E. Burns, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, Adam Zadrozny
A Joint FermiGbm And Ligo/Virgo Analysis Of Compact Binary Mergers From The First And Second GravitationalWave Observing Runs, R. Hamburg, C. Fletcher, E. Burns, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, Adam Zadrozny
Physics and Astronomy Faculty Publications and Presentations
We present results from offline searches of Fermi Gammaray Burst Monitor (GBM) data for gammaray transients coincident with the compact binary coalescences observed by the gravitationalwave (GW) detectors Advanced LIGO and Advanced Virgo during their first and second observing runs. In particular, we perform followup for both confirmed events and low significance candidates reported in the LIGO/Virgo catalog GWTC1. We search for temporal coincidences between these GW signals and GBMtriggered gammaray bursts (GRBs). We also use the GBM Untargeted and Targeted subthreshold searches to find coincident gammarays below the onboard triggering threshold. This work implements a refined statistical approach ...
LongRange Electroweak Amplitudes Of Single Hadrons From Euclidean FiniteVolume Correlation Functions, Raúl A. Briceño, Zohreh Davoudi, Maxwell T. Hansen, Matthias R. Schindler, Alessandro Baroni
LongRange Electroweak Amplitudes Of Single Hadrons From Euclidean FiniteVolume Correlation Functions, Raúl A. Briceño, Zohreh Davoudi, Maxwell T. Hansen, Matthias R. Schindler, Alessandro Baroni
Physics Faculty Publications
A relation is presented between singlehadron longrange matrix elements defined in a finite Euclidean spacetime and the corresponding infinitevolume Minkowski amplitudes. This relation is valid in the kinematic region where any number of twohadron states can simultaneously go on shell, so that the effects of strongly coupled intermediate channels are included. These channels can consist of nonidentical particles with arbitrary intrinsic spins. The result accommodates general Lorentz structures as well as nonzero momentum transfer for the two external currents inserted between the singlehadron states. The formalism, therefore, generalizes the work by Christ et al. [Phys. Rev. D 91, 114510 (2015 ...
Spectral Singularities With Directional Sensitivity, H. Ramezani
Spectral Singularities With Directional Sensitivity, H. Ramezani
Physics and Astronomy Faculty Publications and Presentations
We propose a class of spectral singularities that are sensitive to the direction of excitation and are arising in nonlinear systems with broken parity symmetry. These spectral singularities are sensitive to the direction of the incident beam and result in diverging transmission and reflection for the left (right) incident while the transmission and reflection of the right (left) side of the system remain finite. For pedagogical reason first, we review the scattering formalism in nonlinear systems using an abstract deltafunction model. Then using a parity symmetry broken nonlinear system consists of two delta functions, one linear and the other nonlinear ...
A Guide To Ligo–Virgo Detector Noise And Extraction Of Transient GravitationalWave Signals, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny
A Guide To Ligo–Virgo Detector Noise And Extraction Of Transient GravitationalWave Signals, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny
Physics and Astronomy Faculty Publications and Presentations
The LIGO Scientific Collaboration and the Virgo Collaboration have cataloged eleven confidently detected gravitationalwave events during the first two observing runs of the advanced detector era. All eleven events were consistent with being from wellmodeled mergers between compact stellarmass objects: black holes or neutron stars. The data around the time of each of these events have been made publicly available through the gravitationalwave open science center. The entirety of the gravitationalwave strain data from the first and second observing runs have also now been made publicly available. There is considerable interest among the broad scientific community in understanding the data ...
Model Comparison From Ligo–Virgo Data On Gw170817’S Binary Components And Consequences For The Merger Remnant, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny
Model Comparison From Ligo–Virgo Data On Gw170817’S Binary Components And Consequences For The Merger Remnant, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, M. Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny
Physics and Astronomy Faculty Publications and Presentations
GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitationalwave data alone does not rule out the possibility that one or both objects were lowmass black holes ...
Robust Localized ZeroEnergy Modes From Locally Embedded PtSymmetric Defects, Fatemeh Mostafavi, Cem Yuce, Omar S. MaganaLoaiza, Henning Schomerus, H. Ramezani
Robust Localized ZeroEnergy Modes From Locally Embedded PtSymmetric Defects, Fatemeh Mostafavi, Cem Yuce, Omar S. MaganaLoaiza, Henning Schomerus, H. Ramezani
Physics and Astronomy Faculty Publications and Presentations
We demonstrate the creation of robust localized zeroenergy states that are induced into topologically trivial systems by insertion of a PTsymmetric defect with local gain and loss. A pair of robust localized states induced by the defect turns into zeroenergy modes when the gainloss contrast exceeds a threshold, at which the defect states encounter an exceptional point. Our approach can be used to obtain robust lasing or perfectly absorbing modes in any part of the system.