Elasticity Of Cylindrical Black Holes, 2016 California Polytechnic State University, San Luis Obispo

#### Elasticity Of Cylindrical Black Holes, Conrad Pearson

*Physics*

Black holes are regions of strong gravity, and are often regarded as behaving like drops of fluid. When this line of thought is applied to cylindrical black holes (black cylinders), a mapping can be made between known instabilities for black cylinders and ordinary fluid cylinders. However, this known correlation is increasingly less accurate for lower spatial dimensions, and I seek to correct this discrepancy in this thesis. By considering soft solids instead of pure fluids, elastic energy can be included, which brings us closer to a direct comparison. In improving this mapping, it becomes possible to better understand the behavior ...

Black Holes Modeled As Fluid Droplets On Membranes, 2016 California Polytechnic State University, San Luis Obispo

#### Black Holes Modeled As Fluid Droplets On Membranes, Anthony Bardessono

*Physics*

No abstract provided.

Schwarzschild Spacetime And Friedmann-Lemaitre-Robertson-Walker Cosmology, 2016 University of Connecticut - Storrs

#### Schwarzschild Spacetime And Friedmann-Lemaitre-Robertson-Walker Cosmology, Zachary Cohen

*Honors Scholar Theses*

The advent of General Relativity via Einstein's field equations revolutionized our understanding of gravity in our solar system and universe. The idea of General Relativity posits that gravity is entirely due to the geometry of the universe -- that is, the mass distribution throughout the universe results in the ``curving" of spacetime, which gives us the physics we see on a large scale. In the framework of General Relativity, we find that the universe behaves differently than was predicted in the model of gravitation developed by Newton. We will derive the general relativistic model for a simple system near a ...

Better Together, 2016 DePaul University

#### Better Together

*DePaul Magazine*

Faculty have taken full advantage of the university's innovative intercollegiate grant program, and the resulting research is as interesting and diverse as the collaborators themselves. What is resulting is research on "Patient and Primary Care Provider Perspectives on Recreational and Therapeutic Cannabis Use Within a Changing Socioculltural and Political Context;" a new minor in climate change science and policy; a new class, Communication, Coding and Entrepreneurship; brain inflammation research; and the project "Cosmology Meets Continental Philosophy: Natural Laws and Why There Is Something Rather Than Nothing"

The Geometry Of Spacetime And Its Singular Nature, 2016 University of Connecticut

#### The Geometry Of Spacetime And Its Singular Nature, Filip Dul

*Honors Scholar Theses*

One hundred years ago, Albert Einstein revolutionized our understanding of gravity, and thus the large-scale structure of spacetime, by implementing differential geometry as the pri- mary medium of its description, thereby condensing the relationship between mass, energy and curvature of spacetime manifolds with the Einstein field equations (EFE), the primary compo- nent of his theory of General Relativity. In this paper, we use the language of Semi-Riemannian Geometry to examine the Schwarzschild and the Friedmann-Lemaˆıtre-Robertson-Walker met- rics, which represent some of the most well-known solutions to the EFE. Our investigation of these metrics will lead us to the problem of ...

Hawking Radiation Screening And Penrose Process Shielding In The Kerr Black Hole, 2016 Dublin Institute of Technology

#### Hawking Radiation Screening And Penrose Process Shielding In The Kerr Black Hole, Eamon Mc Caughey

*Articles*

** **The radial motion of massive particles in the equatorial plane of aKerr black hole is considered. Screening of the Hawking radiation and shielding of the Penrose process are examined (both inside and outside the ergosphere) and their effect on the evaporation of the black hole is studied. In particular, the locus and width of a classically forbidden region and their dependence on the particle’s angular momentum and energy is analysed. Tunneling of particles between the boundaries of this region is considered and the transmission coefficient determined.

The Differentialgeometry Package, 2016 Utah State University

#### The Differentialgeometry Package, Ian M. Anderson, Charles G. Torre

*Downloads*

This is the entire DifferentialGeometry package, a zip file (DifferentialGeometry.zip) containing (1) a Maple Library file, DifferentialGeometryUSU.mla, (2) a Maple help file DifferentialGeometry.help. This is the latest version of the DifferentialGeometry software; it supersedes what is released with Maple. It has been tested on Maple versions 17, 18, 2015.

Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah (In Press), 2016 Embry-Riddle Aeronautical University

#### Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah (In Press), T. Yuan, C. Heale, J. Snively, X. Cai, P. Pautet, C. Fish, Y. Zhao, M. Taylor, W. Pendelton, V. Wickwar, N. Mitchell

*Jonathan B. Snively*

Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, 2016 Loyola University Chicago

#### Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann

*Robert A McNees IV*

A variational formulation is given for a theory of gravity coupled to a massive vector in four dimensions, with Asymptotically Lifshitz boundary conditions on the fields. For theories with critical exponent z=2 we obtain a well-defined variational principle by explicitly constructing two actions with local boundary counterterms. As part of our analysis we obtain solutions of these theories on a neighborhood of spatial infinity, study the asymptotic symmetries, and consider different definitions of the boundary stress tensor and associated charges. A constraint on the boundary data for the fields figures prominently in one of our formulations, and in that ...

Black Holes In The Conical Ensemble, 2016 Loyola University Chicago

#### Black Holes In The Conical Ensemble, Robert Mcnees, Daniel Grumiller

*Robert A McNees IV*

We consider black holes in an “unsuitable box”: a finite cavity coupled to a thermal reservoir at a temperature different than the black hole’s Hawking temperature. These black holes are described by metrics that are continuous but not differentiable due to a conical singularity at the horizon. We include them in the Euclidean path integral sum over configurations, and analyze the effect this has on black hole thermodynamics in the canonical ensemble. Black holes with a small deficit (or surplus) angle may have a smaller internal energy or larger density of states than the nearby smooth black hole, but ...

Conventions, Definitions, Identities, And Other Useful Formulae, 2016 Loyola University Chicago

#### Conventions, Definitions, Identities, And Other Useful Formulae, Robert Mcnees

*Robert A McNees IV*

As the name suggests, these notes contain a summary of important conventions, definitions, identities, and various formulas that I often refer to. They may prove useful for researchers working in General Relativity, Supergravity, String Theory, Cosmology, and related areas.

Boundary Terms Unbound! Holographic Renormalization Of Asymptotically Linear Dilaton Gravity, 2016 Loyola University Chicago

#### Boundary Terms Unbound! Holographic Renormalization Of Asymptotically Linear Dilaton Gravity, Robert Mcnees, Robert Mann

*Robert A McNees IV*

A variational principle is constructed for gravity coupled to an asymptotically linear dilaton and a p-form field strength. This requires the introduction of appropriate surface terms—also known as 'boundary counterterms'—in the action. The variation of the action with respect to the boundary metric yields a boundary stress tensor, which is used to construct conserved charges that generate the asymptotic symmetries of the theory. In most cases a minimal set of assumptions leads to a unique set of counterterms. However, for certain examples we find families of actions that depend on one or more continuous parameters. We show that ...

Differentialgeometry In Brno, 2015 Utah State University

#### Differentialgeometry In Brno, Ian M. Anderson

*Presentations*

This page will provide files supporting Ian Anderson's presentations in Brno, December 2015. The files can be found and downloaded from "Additional Files", below.

The files include:

(1) DifferentialGeometryUSU.mla: This is the Maple Library Archive file which provides all the DifferentialGeometry functionality. Here are Installation Instructions.

(2) DifferentialGeometry.help : this is the latest version of the DifferentialGeometry documentation. Copy this file to the same directory used for DifferentialGeometryUSU.mla (from step (1)).

Probabilistic Reasoning In Cosmology, 2015 The University of Western Ontario

#### Probabilistic Reasoning In Cosmology, Yann Benétreau-Dupin

*Electronic Thesis and Dissertation Repository*

Cosmology raises novel philosophical questions regarding the use of probabilities in inference. This work aims at identifying and assessing lines of arguments and problematic principles in probabilistic reasoning in cosmology.

The first, second, and third papers deal with the intersection of two distinct problems: accounting for selection effects, and representing ignorance or indifference in probabilistic inferences. These two problems meet in the cosmology literature when anthropic considerations are used to predict cosmological parameters by conditionalizing the distribution of, e.g., the cosmological constant on the number of observers it allows for. However, uniform probability distributions usually appealed to in such ...

On The Existence And Uniqueness Of Static, Spherically Symmetric Stellar Models In General Relativity, 2015 University of Tennessee - Knoxville

#### On The Existence And Uniqueness Of Static, Spherically Symmetric Stellar Models In General Relativity, Josh Michael Lipsmeyer

*Masters Theses*

The "Fluid Ball Conjecture" states that a static stellar model is spherically symmetric. This conjecture has been the motivation of much work since first mentioned by Kunzle and Savage in 1980. There have been many partial results( ul-Alam, Lindblom, Beig and Simon,etc) which rely heavily on arguments using the positive mass theorem and the equivalence of conformal flatness and spherical symmetry. The purpose of this paper is to outline the general problem, analyze and compare the key differences in several of the partial results, and give existence and uniqueness proofs for a particular class of equations of state which ...

Models Of Time Travel And Their Consequences, 2015 Oglethorpe University

#### Models Of Time Travel And Their Consequences, Antonio Mantica

*Antonio M. Mantica*

How do we travel through time? We know that we can move forward in it (we have no choice), but can we jump forward in time? Can we go backward in time? It also gives rise to other troubling questions: is time measurable in distinct increments, or does it flow continuously? In "Models of Time Travel and their Consequences," Antonio Mantica walks the reader through current understandings of how time functions in Einstein's universe and proposes three distinct models to explain it. Following that, he provides a list of experiments to credit or discredit the models. Appropriate for audiences ...

Clea Labs For Stellar And Cosmological Astronomy Bottled For Macintosh, 2015 Portland State University

#### Clea Labs For Stellar And Cosmological Astronomy Bottled For Macintosh, Joel Cranston, Jack Straton

*Jack C. Straton*

Project CLEA -- *CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY* -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs are developed for Windows but PSU student Joel Cranston has bottled them for Intel Macintosh computers.

Clea Labs For Planetary Astronomy Bottled For Macintosh, 2015 Portland State University

#### Clea Labs For Planetary Astronomy Bottled For Macintosh, Joel Cranston, Jack Straton

*Jack C. Straton*

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images. These Labs are developed for Windows but PSU student Joel Cranston has bottled them for Intel Macintosh computers.

High Gravitational Waveform Accuracy At Null Infinity, 2015 Marshall University

#### High Gravitational Waveform Accuracy At Null Infinity, Maria Babiuc-Hamilton

*Maria Babiuc-Hamilton*

The aim of Cauchy-characteristic extraction is to provide a standardized waveform extraction tool for the numerical relativity community. The new extraction tool contains major improvements and corrections to previous versions and displays convergence. The error introduced by CCE satisfies the time domain criteria required for advanced LIGO data analysis. The importance of accurate waveforms to the gravitational wave astronomy has created an urgency for tools like CCE. The source code has been released to the public and is available as part of the Einstein Toolkit. We welcome applications to a variety of generic Cauchy codes implementing Einstein Equations of General ...

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, 2015 Department of Physics, Utah State University

#### Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles Torre, Dionisios Krongos

*Charles G. Torre*

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and electromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equations are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Geometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and formulas for constructing the scalar field from ...