Physics Commons^™

Intensities, Broadening And Narrowing Parameters In The Ν3 Band Of Methane, Et-Touhami Es-Sebbar, Aamir Farooq

Dr. Et-touhami Es-sebbar

The P-branch of methane׳s ν3 band is probed to carry out an extensive study of the 2905–2908 cm−1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001 cm−1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.

C/2013 R1 (Lovejoy) At Ir Wavelengths And The Variability Of Co Abundances Among Oort Cloud Comets, L. Paganini, M. J. Mumma, G. L. Villanueva, J. V. Keane, G. A. Blake, B. P. Bonev, M. A. Disanti, E. L. Gibb, K. J. Meech

Erika Gibb

Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner

Jay S Huebner

Providing the tools and know-how to apply the principles of astronomy first-hand, these 43 laboratory exercises each contain an introduction that clearly shows budding astronomers why the particular topic of that lab is of interest and relevant to astronomy. About one-third of the exercises are devoted solely to observation, and no mathematics is required beyond simple high school algebra and trigonometry.Organizes exercises into six major topics—sky, optics and spectroscopy, celestial mechanics, solar system, stellar properties, and exploration and other topics—providing clear outlines of what is involved in the exercise, its purpose, and what procedures and apparatus are to be used. …

Finite Difference Schemes For Second Order Systems Describing Black Holes, Mohammad Motamed, Maria Babiuc-Hamilton, B. Szilágyi, H-O. Kreiss, J. Winicour

Maria Babiuc-Hamilton

In the harmonic description of general relativity, the principal part of Einstein’s equations reduces to 10 curved space wave equations for the components of the space-time metric. We present theorems regarding the stability of several evolution-boundary algorithms for such equations when treated in second order differential form. The theorems apply to a model black hole space-time consisting of a spacelike inner boundary excising the singularity, a timelike outer boundary and a horizon in between. These algorithms are implemented as stable, convergent numerical codes and their performance is compared in a 2-dimensional excision problem.

Dark Matter As An Integral Part Of An Alternative Gravity Model, Hontas Farmer

Hontas F Farmer

The purpose of this paper is to reconcile observations of dark matter effects on the galactic and cosmological scales with the null results of astroparticle physics observations such as CDMS and ANTARES. This paper will also provide a candidate unified and simpler mathematical formulation for the Lambda CDM model. Unification is achieved by a combination of the f(R) approach, with the standard LCDM approach and inflationary models. It is postulated that dark matter-energy fields depend on the Ricci curvature R. Standard methods of classical and quantum field theory on curved space time are applied. When this model is treated as …

Conformal Gravity Holography In Four Dimensions, Robert Mcnees

Robert A McNees IV

We formulate four-dimensional conformal gravity with (anti–)de Sitter boundary conditions that are weaker than Starobinsky boundary conditions, allowing for an asymptotically subleading Rindler term concurrent with a recent model for gravity at large distances. We prove the consistency of the variational principle and derive the holographic response functions. One of them is the conformal gravity version of the Brown–York stress tensor, the other is a “partially massless response”. The on shell action and response functions are finite and do not require holographic renormalization. Finally, we discuss phenomenologically interesting examples, including the most general spherically symmetric solutions and rotating black hole …