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All Articles in Cosmology, Relativity, and Gravity

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Sources Of Gravity.Docx, Vildyan Yanbikov 2017 Yanbikov Vildyan Shavkyatovich

Sources Of Gravity.Docx, Vildyan Yanbikov

Vildyan Yanbikov

Computed coefficients of gravity. (gravitational constant) in the center and the surface of the Sun. The computed critical parameters. a slowly rotating neutron star. In her state of the instability (before it exploded). Checked the assumption about the rate of transmission of gravitational interactions. Using the given method it is possible to calculate the coefficient of gravity away from the powerful gravity source.                                                                  


Empty Universe.Docx, Vildyan Yanbikov 2017 Yanbikov Vildyan Shavkyatovich

Empty Universe.Docx, Vildyan Yanbikov

Vildyan Yanbikov

Calculated the speed of propagation of gravity in space. ( the speed of gravity waves). The computed gravitational constant for the “empty” space.


Quantum Physics And Relativity In Lovecraft's Fiction, Garrison McCammon 2017 Ursinus College

Quantum Physics And Relativity In Lovecraft's Fiction, Garrison Mccammon

English Summer Fellows

The early twentieth century brought about some of the best and most influential horror or weird tales ever written in the English speaking world. The most impressive and most lauded author of the group composed of such figures as Algernon Blackwood, M. R. James, Arthur Machen, Clark A. Smith, and Robert E. Howard was H. P. Lovecraft. Posthumously declared the literary successor to Edgar Allan Poe, Lovecraft’s fiction and tales of terror have cast such a huge shadow that every significant author in weird writing since his passing has claimed him as a literary heir. Lovecraft’s works were ...


Gravitational Wave Behavior At A Vacuum-Matter Interface, Jake Litterer 2017 University of Puget Sound

Gravitational Wave Behavior At A Vacuum-Matter Interface, Jake Litterer

Honors Program Theses

In classical electrodynamics, boundary conditions of the E and B fields are derived from Maxwell's equations, which are used to derive the Fresnel equations describing the behavior of a wave at an interface between media with given indices of refraction. Though electrodynamics and gravity are in some instances strikingly analogous, boundary conditions in general relativity are somewhat more opaque. We will see that while while continuity of the metric must be true in general, discontinuity of the extrinsic curvature of spacetime, while allowed by the Einstein field equations, results in a singularity in the energy-momentum tensor. This singularity is ...


Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman 2017 International Islamic University - Malaysia

Literature Review: Biomimetic And Conventional Aircraft Wing Tips, Naseeb Ahmed Siddiqui, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

This paper is an attempt to summarize the effect of wing tip devices employed by birds, as well as aeronautical engineers in the past to improve the performance characteristics of aircraft. The focus is on reduction of the induced drag or drag due to lift also known as inviscid drag. This paper will provide an insight on both biomimetic and conventional wing tip approaches to reduce the induced drag. Prior analysis and experiments on the aerodynamics of airplane performance due to both these separate studies have been discussed. The needs of the industry and their past inventions have been described ...


An Analysis Of The Effects Of Isocurvature Fluctuations In Dantes Inferno Multi-Field Inflation Models, Brandon M. Buncher 2017 College of William and Mary

An Analysis Of The Effects Of Isocurvature Fluctuations In Dantes Inferno Multi-Field Inflation Models, Brandon M. Buncher

Undergraduate Honors Theses

Although there is significant evidence of inflation (a period of rapid expansion of the early universe), a definitive model of the epoch has not yet been widely accepted. A variety of models exist which describe this period; however, current technology cannot adequately measure several key factors that would demonstrate the veracity of these models. A major differentiator between classes of models is the number of fields that contribute to the inflationary epoch. Single-field inflation models assume the existence of a single field, though the details of this field vary depending on the model, while multi-field inflation models assume the existence ...


Fermi-Lat Daily Monitoring Observations Of The Microquasar Cygnus X-1, Austin P. Waldron, Stephen R. Hood, Arash Bodaghee 2017 Georgia College and State University

Fermi-Lat Daily Monitoring Observations Of The Microquasar Cygnus X-1, Austin P. Waldron, Stephen R. Hood, Arash Bodaghee

Georgia College Student Research Events

Detection of gamma-ray emission from microquasars is important for understanding particle acceleration in the jet, and for constraining leptonic/hadronic emission models. We present a continuation of a 1-d likelihood analysis on gamma-ray observations by Fermi-LAT (0.1-10 GeV) of the accreting black hole candidate Cygnus X-1. Combining this gamma-ray data with available X-ray monitoring data from Swift and MAXI allowed us to reveal over a dozen days (in 2008-2016) during which Cyg X-1 displayed low-significance (3-4 sigma) excesses, many of which were contemporaneous with apparent transitions in the X-rays.


Vacuum.Doc, Vildyan Yanbikov 2017 Yanbikov Vildyan Shavkyatovich

Vacuum.Doc, Vildyan Yanbikov

Vildyan Yanbikov

The calculated density of the physical vacuum. The high density of physical vacuum.              


Evolution Of Cosmic Filaments And Of Their Galaxy Population From Mhd Cosmological Simulations., C. Gheller, F. Vazza, M. Brüggen, M. Alpaslan, Benne W. Holwerda 2017 Swiss National Supercomputing Centre

Evolution Of Cosmic Filaments And Of Their Galaxy Population From Mhd Cosmological Simulations., C. Gheller, F. Vazza, M. Brüggen, M. Alpaslan, Benne W. Holwerda

Benne Holwerda

Despite containing about a half of the total matter in the Universe, at most wavelengths the filamentary structure of the cosmic web is difficult to observe. In this work, we use large unigrid cosmological simulations to investigate how the geometrical, thermodynamical and magnetic properties of cosmological filaments vary with mass and redshift (z ≤ 1). We find that the average temperature, length, volume and magnetic field of filaments scales well with their total mass. This reflects the role of self-gravity in shaping their properties and enables statistical predictions of their observational properties based on their mass. We also focus on the ...


Short-Period Mesospheric Gravity Waves And Their Sources At The South Pole, Dhvanit Mehta, Andrew J. Gerrard, Yusuke Ebihara, Allan T. Weatherwax, Louis J. Lanzerotti 2017 Merrimack College

Short-Period Mesospheric Gravity Waves And Their Sources At The South Pole, Dhvanit Mehta, Andrew J. Gerrard, Yusuke Ebihara, Allan T. Weatherwax, Louis J. Lanzerotti

Physics Faculty Publications

The sourcing locations and mechanisms for short-period, upward-propagating gravity waves at high polar latitudes remain largely unknown. Using all-sky imager data from the Amundsen–Scott South Pole Station, we determine the spatial and temporal characteristics of 94 observed small-scale waves in 3 austral winter months in 2003 and 2004. These data, together with background atmospheres from synoptic and/or climatological empirical models, are used to model gravity wave propagation from the polar mesosphere to each wave's source using a ray-tracing model. Our results provide a compelling case that a significant proportion of the observed waves are launched in several ...


Series Solutions Of Polarized Gowdy Universes, Doniray Brusaferro 2017 Virginia Commonwealth University

Series Solutions Of Polarized Gowdy Universes, Doniray Brusaferro

Theses and Dissertations

Einstein's field equations are a system of ten partial differential equations. For a special class of spacetimes known as Gowdy spacetimes, the number of equations is reduced due to additional structure of two dimensional isometry groups with mutually orthogonal Killing vectors. In this thesis, we focus on a particular model of Gowdy spacetimes known as the polarized T3 model, and provide an explicit solution to Einstein's equations.


Effects Of Low-Temperature Reheating On The Matter Power Spectrum, Jonah Kudler-Flam 2017 Colgate University

Effects Of Low-Temperature Reheating On The Matter Power Spectrum, Jonah Kudler-Flam

Senior Honors Theses

The thermal and expansion history of the universe between inflation and big bang nucleosynthesis is largely unconstrained. In standard cosmological theories, highly relativistic standard model particles dominate the universe’s energy density during this epoch. We consider a non-standard cosmology consisting of an era dominated by an oscillating scalar field that behaves similarly to matter. The growth of density perturbations is strongly enhanced in an early matter dominated era (EMDE), leading to potentially profound consequences regarding the dynamics of the early universe and the scales of the first bound dark matter structures. We investigate the applications and validity of the ...


Gravity Wave And Turbulence Transport In The Mesopause Region, Yafang Guo 2017 Embry-Riddle Aeronautical University

Gravity Wave And Turbulence Transport In The Mesopause Region, Yafang Guo

Dissertations and Theses

Vertical transport due to dissipating gravity waves and turbulence in the mesopause region (85-100 km) are analyzed with observational data obtained from a narrow-band sodium wind/temperature lidar located at Andes Lidar Observatory (ALO), Cerro Pach´on (30.25 S, 70.73 W), Chile. The Na lidar at ALO has been in regular operation since 2010. The upgrade of the lidar system in May 2014 resulted in great improvements of the signal levels, which enabled data acquisition of high temporal and vertical resolutions reaching 6 s and 25 m. Traditional data processing utilizes signals at lower resolutions, typically at 60 ...


Two Topics In Astrophysics: Exoplanetary Gravitational Microlensing And Radio Interferometry, Eleanor Sara Turrell 2017 Bard College

Two Topics In Astrophysics: Exoplanetary Gravitational Microlensing And Radio Interferometry, Eleanor Sara Turrell

Senior Projects Spring 2017

Senior Project submitted to The Division of Science, Mathematics and Computing of Bard College.


Statistical Modeling And Beam Analysis For The Redshifted Global 21 Centimeter Signal, Katherine Pellicore 2017 University of Colorado, Boulder

Statistical Modeling And Beam Analysis For The Redshifted Global 21 Centimeter Signal, Katherine Pellicore

Undergraduate Honors Theses

This thesis explores two aspects of measurements of the global 21 cm signal through analytical simulations. We first attempt to understand how well the global 21 cm signal could be extracted from measurements of the sky. We accomplish this by employing a Fisher matrix analysis to estimate the uncertainties of cosmological parameters for simple measurement models that assume a perfectly calibrated instrument. We find that the assumed parameters of the signal can be constrained to high precision under realistic scenarios of noise and foreground contaminants. We also study the bias in the cosmological parameters due to modeling errors using a ...


Exotic Statistics For Strings In 4d Bf Theory, John C. Baez, Derek K. Wise, Alissa S. Crans 2016 University of California, Riverside

Exotic Statistics For Strings In 4d Bf Theory, John C. Baez, Derek K. Wise, Alissa S. Crans

Alissa Crans

After a review of exotic statistics for point particles in 3d BF theory, and especially 3d quantum gravity, we show that string-like defects in 4d BF theory obey exotic statistics governed by the 'loop braid group'. This group has a set of generators that switch two strings just as one would normally switch point particles, but also a set of generators that switch two strings by passing one through the other. The first set generates a copy of the symmetric group, while the second generates a copy of the braid group. Thanks to recent work of Xiao-Song Lin, we can ...


Elasticity Of Cylindrical Black Holes, Conrad Pearson 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 ...


Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel 2016 University of New Mexico

Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel

Physics & Astronomy ETDs

Various evidence reveals that dark matter is a primary component of this universe. The amount of dark matter is known, but its identity is a mystery. To determine its properties, efforts to detect and produce dark matter are underway. Dark matter annihilations throughout the galaxy may produce photons, neutrinos, and cosmic rays. Neutrino and photon detectors may then indirectly detect dark matter by detecting these annihilation products. The annihilation rate, dark matter mass, and dark matter scattering rate off of matter affect the signals received at Earth. These signals can therefore probe the identity of dark matter, especially if dark ...


Rethinking The Polar Cap: Eccentric Dipole Structuring Of Ulf Power At The Highest Corrected Geomagnetic Latitudes, Kevin D. Urban, Andrew J. Gerrard, Louis J. Lanzerotti, Allan T. Weatherwax 2016 Merrimack College

Rethinking The Polar Cap: Eccentric Dipole Structuring Of Ulf Power At The Highest Corrected Geomagnetic Latitudes, Kevin D. Urban, Andrew J. Gerrard, Louis J. Lanzerotti, Allan T. Weatherwax

Physics Faculty Publications

The day-to-day evolution and statistical features of Pc3-Pc7 band ultralow frequency (ULF) power throughout the southern polar cap suggest that the corrected geomagnetic (CGM) coordinates do not adequately organize the observed hydromagnetic spatial structure. It is shown that that the local-time distribution of ULF power at sites along CGM latitudinal parallels exhibit fundamental differences and that the CGM latitude of a site in general is not indicative of the site's projection into the magnetosphere. Thus, ULF characteristics observed at a single site in the polar cap cannot be freely generalized to other sites of similar CGM latitude but separated ...


Introduction To Classical Field Theory, Charles G. Torre 2016 Department of Physics, Utah State University

Introduction To Classical Field Theory, Charles G. Torre

All Complete Monographs

This is an introduction to classical field theory. Topics treated include: Klein-Gordon field, electromagnetic field, scalar electrodynamics, Dirac field, Yang-Mills field, gravitational field, Noether theorems relating symmetries and conservation laws, spontaneous symmetry breaking, Lagrangian and Hamiltonian formalisms.


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