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Full-Text Articles in Physical Sciences and Mathematics

Implementing A Self-Corrected Chemical Potential Scheme In Determinant Quantum Monte Carlo Simulations, Kevin Gordon Kleiner May 2019

Implementing A Self-Corrected Chemical Potential Scheme In Determinant Quantum Monte Carlo Simulations, Kevin Gordon Kleiner

University of Tennessee Honors Thesis Projects

No abstract provided.


Juxtaposition At 45 Km Of Temperatures From Rayleigh-Scatter Lidar And Reanalysis Models, David K. Moser May 2019

Juxtaposition At 45 Km Of Temperatures From Rayleigh-Scatter Lidar And Reanalysis Models, David K. Moser

All Graduate Theses and Dissertations

Weather and climate forecasts are almost exclusively produced by computer models, which use atmospheric measurements as starting points. It is a well-known and joked-about fact that model predictions can be incorrect at times. One of the reasons this happens is due to gaps in our knowledge of atmospheric conditions in areas where measurements don’t often taken place, such as the mesosphere, which stretches from roughly 45-90 km altitude.

A lidar is a device that can shoot out short bursts of laser light to measure things such as atmospheric thickness at a distance. From this information one can then derive ...


University Physics I: Classical Mechanics, Julio Gea-Banacloche Feb 2019

University Physics I: Classical Mechanics, Julio Gea-Banacloche

Open Educational Resources

This is a “minimalist” textbook for a first semester of university, calculus-based physics, covering classical mechanics (including one chapter on mechanical waves, but excluding fluids), plus a brief introduction to thermodynamics. The presentation owes much to Mazur’s The Principles and Practice of Physics: conservation laws, momentum and energy, are introduced before forces, and one-dimensional setups are thoroughly explored before two-dimensional systems are considered. It contains both problems and worked-out examples.


Magnetic Resonance Studies Of Free Radicals Generation And Their Impact In Different Polymers, Sunita Humagain Feb 2019

Magnetic Resonance Studies Of Free Radicals Generation And Their Impact In Different Polymers, Sunita Humagain

All Dissertations, Theses, and Capstone Projects

Studies of free radicals in the physics, chemistry, biology, and materials science have contributed to advancements in those fields. The presence of radicals can damage the material and system in some instances and, in some cases, they may enhance the property of the material as well. Knowledge of free radical transformations helps in resilience of certain polymers and inhibition of the oxidation of food and medicine. In this thesis, using the magnetic resonance techniques, EPR and NMR, the generation of free radicals and their effect on the structure of the material is being studied.

Kapton Polyimide (PI, Kapton®) used in ...


Emergent Critical Properties In Liquid-Gas Transition And Single Dislocations In Solid He4, Max Yarmolinsky Feb 2019

Emergent Critical Properties In Liquid-Gas Transition And Single Dislocations In Solid He4, Max Yarmolinsky

All Dissertations, Theses, and Capstone Projects

My research focuses on the analytical and numerical study of seemingly completely different systems - the classical critical point of the liquid-gas transition and a quantum topological defect (dislocation) in solid Helium-4. The unifying theme, though, is Emergence - the appearance of unexpected qualities at large distance and time scales in these systems. Our results resolve the long standing controversy about the nature of the liquid-gas criticality by showing with high confidence that it is the same as that of Ising ferromagnet. In solid 4He, a quantum superclimbing dislocation, which is expected to be violating space-time symmetry according to the elementary ...


Comforting With Mathematics: A Case Study, Michael J. Goldstein Jan 2019

Comforting With Mathematics: A Case Study, Michael J. Goldstein

Journal of Humanistic Mathematics

Death by suicide often leaves behind grieving family members with unanswered questions. Of these concerns, fear that their loved one suffered or felt regret is common. When the method of suicide was jumping from height, that answer can easily be determined using basic kinematics. Despite the perception that mathematics is a cold, calculating field, it can provide a clear, definitive answer and comfort those left behind.


Comparisons Of Performance Between Quantum And Classical Machine Learning, Christopher Havenstein, Damarcus Thomas, Swami Chandrasekaran Jan 2019

Comparisons Of Performance Between Quantum And Classical Machine Learning, Christopher Havenstein, Damarcus Thomas, Swami Chandrasekaran

SMU Data Science Review

In this paper, we present a performance comparison of machine learning algorithms executed on traditional and quantum computers. Quantum computing has potential of achieving incredible results for certain types of problems, and we explore if it can be applied to machine learning. First, we identified quantum machine learning algorithms with reproducible code and had classical machine learning counterparts. Then, we found relevant data sets with which we tested the comparable quantum and classical machine learning algorithm's performance. We evaluated performance with algorithm execution time and accuracy. We found that quantum variational support vector machines in some cases had higher ...


High Throughput, Automated Prediction Of Focusing Patterns For Inertial Microfluidics, Aditya Kommajosula, Jeong-Ah Kim, Wonhee Lee, Baskar Ganapathysubramanian Jan 2019

High Throughput, Automated Prediction Of Focusing Patterns For Inertial Microfluidics, Aditya Kommajosula, Jeong-Ah Kim, Wonhee Lee, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Visual inspections for identifying focusing points in inertial microfluidic flows are prone to misinterpreting stable locations and focusing shifts in the case of non-trivial focusing patterns. We develop and deploy an approach for automating the calculation of focusing patterns for a general channel geometry, and thereby reduce the dependence on empirical/visual procedures to confirm the presence of stable locations. We utilize concepts from interpolation theory (to represent continuous force-fields using discrete points), and stability theory to identify "basins of attraction" and quantitatively identify stable equilibrium points. Our computational experiments reveal that predicting equilibrium points accurately requires upto ×10-20 times ...


Understanding Higher-Order Nonlocal Halo Bias At Large Scales By Combining The Power Spectrum With The Bispectrum, Shun Saito, Tobias Baldauf Jan 2019

Understanding Higher-Order Nonlocal Halo Bias At Large Scales By Combining The Power Spectrum With The Bispectrum, Shun Saito, Tobias Baldauf

Shun Saito

Understanding the relation between underlying matter distribution and biased tracers such as galaxies or dark matter halos is essential to extract cosmological information from ongoing or future galaxy redshift surveys. At sufficiently large scales such as the baryon acoustic oscillation (BAO) scale, a standard approach for the bias problem on the basis of the perturbation theory (PT) is to assume the "local bias" model in which the density field of biased tracers is deterministically expanded in terms of matter density field at the same position. The higher-order bias parameters are then determined by combining the power spectrum with higher-order statistics ...


The Stripe 82 Massive Galaxy Project. Iii. A Lack Of Growth Among Massive Galaxies, Kevin Bundy, Alexie Leauthaud, Shun Saito, Claudia Maraston, David A. Wake, Daniel Thomas Jan 2019

The Stripe 82 Massive Galaxy Project. Iii. A Lack Of Growth Among Massive Galaxies, Kevin Bundy, Alexie Leauthaud, Shun Saito, Claudia Maraston, David A. Wake, Daniel Thomas

Shun Saito

The average stellar mass (M*) of high-mass galaxies (log M*/M > 11.5) is expected to grow by ∼30% since z ~ 1, largely through ongoing mergers that are also invoked to explain the observed increase in galaxy sizes. Direct evidence for the corresponding growth in stellar mass has been elusive, however, in part because the volumes sampled by previous redshift surveys have been too small to yield reliable statistics. In this work, we make use of the Stripe 82 Massive Galaxy Catalog (S82-MGC) to build a mass-limited sample of 41,770 galaxies log M*/M > 11.2) with optical-to-near-IR photometry ...


The Stripe 82 Massive Galaxy Project. I. Catalog Construction, Kevin Bundy, Alexie Leauthaud, Shun Saito Jan 2019

The Stripe 82 Massive Galaxy Project. I. Catalog Construction, Kevin Bundy, Alexie Leauthaud, Shun Saito

Shun Saito

The Stripe 82 Massive Galaxy Catalog (S82-MGC) is the largest-volume stellar mass-limited sample of galaxies beyond z ≈ 0.1 constructed to date. Spanning 139.4 deg2, the S82-MGC includes a mass-limited sample of 41,770 galaxies with log M*/M ≳ 11.2 to z ≈ 0.7, sampling a volume of 0.3 Gpc3, roughly equivalent to the volume of the Sloan Digital Sky Survey-I/II (SDSS-I/II) z < 0.15 main sample. The catalog is built on three pillars of survey data: the SDSS Stripe 82 Coadd photometry which reaches r-band magnitudes of ∼23.5 AB, Y JHK photometry at depths of 20th magnitude (AB) from the UK Infrared Deep Sky Survey Large Area Survey, and over 70,000 spectroscopic galaxy redshifts from the SDSS-I/II and the Baryon Oscillation Spectroscopic Survey. We describe the catalog construction and verification, the production of 9-band matched aperture photometry, tests of existing and newly estimated photometric redshifts required to supplement spectroscopic redshifts for 55% of the log M*/M ≳ 11.2 sample, and geometric masking. We provide near-IR based stellar mass estimates and compare these to previous estimates. All catalog products are made publicly available. The S82-MGC not ...


The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Testing Gravity With Redshift Space Distortions Using The Power Spectrum Multipoles, Florian Beutler, Shun Saito Jan 2019

The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Testing Gravity With Redshift Space Distortions Using The Power Spectrum Multipoles, Florian Beutler, Shun Saito

Shun Saito

We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, which consists of 690 827 galaxies in the redshift range 0.43 < z < 0.7 and has a sky coverage of 8498 deg2. We perform our analysis in Fourier space using a power spectrum estimator suggested by Yamamoto et al. We measure the multipole power spectra in a self-consistent manner for the first time in the sense that we provide a proper way to treat the survey window function and the integral constraint, without the commonly used assumption of an isotropic power spectrum and without the need to split the survey into ...


The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Signs Of Neutrino Mass In Current Cosmological Data Sets, Florian Beutler, Shun Saito Jan 2019

The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Signs Of Neutrino Mass In Current Cosmological Data Sets, Florian Beutler, Shun Saito

Shun Saito

We investigate the cosmological implications of the latest growth of structure measurement from the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 with particular focus on the sum of the neutrino masses, Σmv. We examine the robustness of the cosmological constraints from the baryon acoustic oscillation (BAO) scale, the Alcock-Paczynski effect and redshift-space distortions (DV/rs, FAP, fσ8) of Beutler et al., when introducing a neutrino mass in the power spectrum template. We then discuss how the neutrino mass relaxes discrepancies between the cosmic microwave background (CMB) and other low-redshift measurements within Λ cold ...


The Clustering Of Galaxies In The Completed Sdss-Iii Baryon Oscillation Spectroscopic Survey: Observational Systematics And Baryon Acoustic Oscillations In The Correlation Function, Ashley J. Ross, Florian Beutler, Shun Saito Jan 2019

The Clustering Of Galaxies In The Completed Sdss-Iii Baryon Oscillation Spectroscopic Survey: Observational Systematics And Baryon Acoustic Oscillations In The Correlation Function, Ashley J. Ross, Florian Beutler, Shun Saito

Shun Saito

We present baryon acoustic oscillation (BAO) scale measurements determined from the clustering of 1.2 million massive galaxies with redshifts 0.2 < z < 0.75 distributed over 9300 deg2, as quantified by their redshift-space correlation function. In order to facilitate these measurements, we define, describe, and motivate the selection function for galaxies in the final data release (DR12) of the SDSS III Baryon Oscillation Spectroscopic Survey (BOSS). This includes the observational footprint, masks for image quality and Galactic extinction, and weights to account for density relationships intrinsic to the imaging and spectroscopic portions of the survey. We simulate the observed systematic trends in mock galaxy samples ...


The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations In The Data Releases 10 And 11 Galaxy Samples, Lauren Anderson, Eric Aubourg, Shun Saito Jan 2019

The Clustering Of Galaxies In The Sdss-Iii Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations In The Data Releases 10 And 11 Galaxy Samples, Lauren Anderson, Eric Aubourg, Shun Saito

Shun Saito

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations (BAO) in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey, which is part of the Sloan Digital Sky Survey III. Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range 0.2 < z < 0.7. We also compare these results with those from the publicly released DR9 and DR10 samples. Assuming a concordance Λ cold dark matter (ΛCDM) cosmological model, the DR11 sample covers a volume of 13 Gpc3 and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the BAO feature. The acoustic ...


Simulations Of Baryon Acoustic Oscillations. Ii. Covariance Matrix Of The Matter Power Spectrum, Ryuichi Takahashi, Naoki Yoshida, Masahiro Takada, Takahiko Matsubara, Naoshi Sugiyama, Issha Kayo, Atsushi J. Nishizawa, Takahiro Nishimichi, Shun Saito, Atsushi Taruya Jan 2019

Simulations Of Baryon Acoustic Oscillations. Ii. Covariance Matrix Of The Matter Power Spectrum, Ryuichi Takahashi, Naoki Yoshida, Masahiro Takada, Takahiko Matsubara, Naoshi Sugiyama, Issha Kayo, Atsushi J. Nishizawa, Takahiro Nishimichi, Shun Saito, Atsushi Taruya

Shun Saito

We use 5000 cosmological N-body simulations of 1 h-3 Gpc3 box for the concordance ËCDM model in order to study the sampling variances of a nonlinear matter power spectrum. We show that the non-Gaussian errors can be important even on large length scales relevant for baryon acoustic oscillations (BAOs). Our findings are the following: (1) the non-Gaussian errors degrade the cumulative signal-to-noise ratios (S/Ns) for the power spectrum amplitude by up to a factor of 2 and 4 for redshifts z = 1 and 0, respectively; (2) there is little information on the power spectrum amplitudes in the ...


Space-Based Gravitational-Wave Detectors Can Determine The Thermal History Of The Early Universe, Kazunori Nakayama, Shun Saito, Yudai Suwa, Jun'ichi Yokoyama Jan 2019

Space-Based Gravitational-Wave Detectors Can Determine The Thermal History Of The Early Universe, Kazunori Nakayama, Shun Saito, Yudai Suwa, Jun'ichi Yokoyama

Shun Saito

It is shown that space-based gravitational-wave detectors such as DECIGO and/or the Big Bang Observer will provide us with invaluable information on the cosmic thermal history after inflation, and they will be able to determine the reheat temperature TR provided that it lies in the range preferred by the cosmological gravitino problem, TR ~ 105-9 GeV. Therefore it is strongly desired that they will be put into practice as soon as possible.


Simultaneous Constraints On The Growth Of Structure And Cosmic Expansion From The Multipole Power Spectra Of The Sdss Dr7 Lrg Sample, Akira Oka, Shun Saito, Takahiro Nishimichi, Atsushi Taruya, Kazuhiro Yamamoto Jan 2019

Simultaneous Constraints On The Growth Of Structure And Cosmic Expansion From The Multipole Power Spectra Of The Sdss Dr7 Lrg Sample, Akira Oka, Shun Saito, Takahiro Nishimichi, Atsushi Taruya, Kazuhiro Yamamoto

Shun Saito

The anisotropic galaxy clustering on large scales provides us with a unique opportunity to probe into the gravity theory through the redshift-space distortions (RSDs) and theAlcock-Paczynski effect. Using the multipole power spectra up to hexadecapole (ℓ = 4), of the luminous red galaxy (LRG) sample in the Data Release 7 (DR7) of the Sloan Digital Sky Survey II (SDSS-II), we obtain simultaneous constraints on the linear growth rate f, angular diameter distance DA, and Hubble parameter H at redshift z = 0.3. For this purpose, we first extensively examine the validity of a theoretical model for the non-linear RSDs using ...


Neutrino Mass Constraint From The Sloan Digital Sky Survey Power Spectrum Of Luminous Red Galaxies And Perturbation Theory, Shun Saito, Masahiro Takada, Atsushi Taruya Jan 2019

Neutrino Mass Constraint From The Sloan Digital Sky Survey Power Spectrum Of Luminous Red Galaxies And Perturbation Theory, Shun Saito, Masahiro Takada, Atsushi Taruya

Shun Saito

We compare the model power spectrum, computed based on perturbation theory, with the power spectrum of luminous red galaxies (LRG) measured from the Sloan Digital Sky Survey Data Release 7 catalog, assuming a flat, cold dark matter-dominated cosmology. The model includes the effects of massive neutrinos, nonlinear matter clustering and nonlinear, scale-dependent galaxy bias in a self-consistent manner. We first test the accuracy of the perturbation theory model by comparing the model predictions with the halo power spectrum in real- and redshift-space, measured from 70 simulation realizations for a cold dark matter model without massive neutrinos. We show that the ...


Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya Jan 2019

Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya

Shun Saito

Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with CMB information. In this paper we develop a method to model galaxy power spectrum in the weakly nonlinear regime for a mixed dark matter [cold dark matter (CDM) plus finite-mass neutrinos] model, based on perturbation theory (PT) whose validity is well tested by simulations for a CDM model. In doing this we carefully study various aspects of the nonlinear clustering (nonlinear neutrino perturbations and the higher-order growth functions), and then arrive at a useful approximation allowing ...


Luminous Red Galaxies In Clusters: Central Occupation, Spatial Distributions And Miscentring, Hanako Hoshino, Alexie Leauthaud, Shun Saito Jan 2019

Luminous Red Galaxies In Clusters: Central Occupation, Spatial Distributions And Miscentring, Hanako Hoshino, Alexie Leauthaud, Shun Saito

Shun Saito

Luminous red galaxies (LRG) from the Sloan Digital Sky Survey are among the best understood samples of galaxies and are employed in a broad range of cosmological studies. In this paper, we study how LRGs occupy massive haloes via counts in clusters and reveal several unexpected trends. Using the red-sequence Matched-filter Probabilistic Percolation (redMaPPer) cluster catalogue, we derive the central occupation of LRGs as a function richness. We show that clusters contain a significantly lower fraction of central LRGs than predicted from the two-point correlation function. At halo masses of 1014.5 M, we find Ncen = 0.73 ...


Lensing Is Low: Cosmology, Galaxy Formation Or New Physics?, Alexie Leauthaud, Shun Saito Jan 2019

Lensing Is Low: Cosmology, Galaxy Formation Or New Physics?, Alexie Leauthaud, Shun Saito

Shun Saito

We present high signal-to-noise galaxy-galaxy lensing measurements of the Baryon Oscillation Spectroscopic Survey constant mass (CMASS) sample using 250 deg2 of weak-lensing data from Canada-France-Hawaii Telescope Lensing Survey and Canada-France-Hawaii Telescope Stripe 82 Survey. We compare this signal with predictions from mock catalogues trained to match observables including the stellar mass function and the projected and twodimensional clustering of CMASS. We show that the clustering of CMASS, together with standard models of the galaxy-halo connection, robustly predicts a lensing signal that is 20-40 per cent larger than observed. Detailed tests show that our results are robust to a variety ...


Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito Jan 2019

Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito

Shun Saito

We present an improved prescription for the matter power spectrum in redshift space taking proper account of both nonlinear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the nonlinear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with the ...


Clustering Of Sloan Digital Sky Survey Iii Photometric Luminous Galaxies: The Measurement, Systematics, And Cosmological Implications, Shirley Ho, Antonio J. Cuesta, Hee-Jong Seo, Roland De Putter, Ashley J. Ross, Martin White, Nikhil Padmanabhan, Shun Saito Jan 2019

Clustering Of Sloan Digital Sky Survey Iii Photometric Luminous Galaxies: The Measurement, Systematics, And Cosmological Implications, Shirley Ho, Antonio J. Cuesta, Hee-Jong Seo, Roland De Putter, Ashley J. Ross, Martin White, Nikhil Padmanabhan, Shun Saito

Shun Saito

The Sloan Digital Sky Survey (SDSS) surveyed 14,555 deg2, and delivered over a trillion pixels of imaging data. We present a study of galaxy clustering using 900,000 luminous galaxies with photometric redshifts, spanning between z = 0.45 and z = 0.65, constructed from the SDSS using methods described in Ross et al. This data set spans 11,000 deg2 and probes a volume of 3 h-3 Gpc3, making it the largest volume ever used for galaxy clustering measurements. We describe in detail the construction of the survey window function and various systematics affecting our ...


Evolution Of Stellar-To-Halo Mass Ratio At Z = 0-7 Identified By Clustering Analysis With The Hubble Legacy Imaging And Early Subaru/Hyper Suprime-Cam Survey Data, Yuichi Harikane, Masami Ouchi, Yoshiaki Ono, Surhud More, Shun Saito Jan 2019

Evolution Of Stellar-To-Halo Mass Ratio At Z = 0-7 Identified By Clustering Analysis With The Hubble Legacy Imaging And Early Subaru/Hyper Suprime-Cam Survey Data, Yuichi Harikane, Masami Ouchi, Yoshiaki Ono, Surhud More, Shun Saito

Shun Saito

We present clustering analysis results from 10,381 Lyman break galaxies (LBGs) at z ∼ 4-7, identified in the Hubble legacy deep imaging and new complimentary large-area Subaru/Hyper Suprime-Cam data. We measure the angular correlation functions of these LBGs at z ∼ 4, 5, 6, and 7 and fit these measurements using halo occupation distribution (HOD) models that provide an estimate of halo masses, Mh ~ (1 - 20 ) x 1011 M. Our Mh estimates agree with those obtained by previous clustering studies in a UV-magnitude versus Mh plane and allow us to calculate stellar-to-halo mass ratios (SHMRs) of ...


Search For Subsolar-Mass Ultracompact Binaries In Advanced Ligo's First Observing Run, B. P. Abbott, Marco Cavaglia Jan 2019

Search For Subsolar-Mass Ultracompact Binaries In Advanced Ligo's First Observing Run, B. P. Abbott, Marco Cavaglia

Marco Cavaglia

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2 M-1.0 M using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2 M, 0.2 M) ultracompact binaries to be less than 1.0x106 Gpc-3 yr-1 and the coalescence rate of a similar distribution of (1.0 M, 1.0 M) ultracompact binaries to be less than 1.9x104 Gpc-3 yr-1 (at 90% confidence). Neither ...


Search For Subsolar-Mass Ultracompact Binaries In Advanced Ligo's First Observing Run, B. P. Abbott, Marco Cavaglia Jan 2019

Search For Subsolar-Mass Ultracompact Binaries In Advanced Ligo's First Observing Run, B. P. Abbott, Marco Cavaglia

Marco Cavaglia

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2 M-1.0 M using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2 M, 0.2 M) ultracompact binaries to be less than 1.0x106 Gpc-3 yr-1 and the coalescence rate of a similar distribution of (1.0 M, 1.0 M) ultracompact binaries to be less than 1.9x104 Gpc-3 yr-1 (at 90% confidence). Neither ...


Gw170817: Measurements Of Neutron Star Radii And Equation Of State, B. P. Abbott, Marco Cavaglia Jan 2019

Gw170817: Measurements Of Neutron Star Radii And Equation Of State, B. P. Abbott, Marco Cavaglia

Marco Cavaglia

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were ...


Hybrid Optical Integrator Based On Silicon-On-Insulator Platform, Taewon Huh Jan 2019

Hybrid Optical Integrator Based On Silicon-On-Insulator Platform, Taewon Huh

Graduate Theses - Physics and Optical Engineering

A hybrid optical integrator is a recirculating loop that performs oversampling typically for analog input, using the cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA). The modulated input signal changes the gain of the loop through XGM and thus modifies the loop accumulation. This thesis presents hybrid optical integrator for an all-optical analog-to-digital converter based on a silicon photonics platform. The device consists of silicon waveguides of dimension 220 × 500 nm (thick × width) and approximately 5 m optical loop length including fiber length, input and output grating couplers for 1550 nm signal, directional couplers, and external components (SOA, optical ...


Thermal Structure Of The Mesopause Region During The Wadis-2 Rocket Campaign, Raimund Wörl, Boris Strelnikov, Timo P. Viehl, Josef Höffner, Pierre-Dominique Pautet, Michael J. Taylor, Yucheng Zhao, Franz-Josef Lübken Jan 2019

Thermal Structure Of The Mesopause Region During The Wadis-2 Rocket Campaign, Raimund Wörl, Boris Strelnikov, Timo P. Viehl, Josef Höffner, Pierre-Dominique Pautet, Michael J. Taylor, Yucheng Zhao, Franz-Josef Lübken

Publications

This paper presents simultaneous temperature measurements by three independent instruments during the WADIS-2 rocket campaign in northern Norway (69 N, 14 E) on 5 March 2015. Vertical profiles were measured in situ with the CONE instrument. Continuous mobile IAP Fe lidar (Fe lidar) measurements during a period of 24 h, as well as horizontally resolved temperature maps by the Utah State University (USU) Advanced Mesospheric Temperature Mapper (AMTM) in the mesopause region, are analysed. Vertical and horizontal temperature profiles by all three instruments are in good agreement. A harmonic analysis of the Fe lidar measurements shows the presence of waves ...