Physics Commons^™

Search For Cosmic Strings In The Cosmos Survey, Jodi L. Christiansen, E. Albin, T. Fletcher, J. Goldman, I. P.W. Teng, M. Foley, G. F. Smoot

Physics

We search the COSMOS survey for pairs of galaxies consistent with the gravitational lensing signature of a cosmic string. The COSMOS survey imaged 1.64 square degrees using the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). Our technique includes estimates of the efficiency for finding the lensed galaxy pair. We find no evidence for cosmic strings with a mass per unit length of Gμ/c² < 3.0 × 10⁻⁷ out to redshifts greater than 0.6 and set 95% upper limits. This corresponds to a global 95% upper limit of Ω_strings < 0.0028.

Entanglement Patterns In Mutually Unbiased Basis Sets, Jay Lawrence

Dartmouth Scholarship

A few simply-stated rules govern the entanglement patterns that can occur in mutually unbiased basis sets (MUBs), and constrain the combinations of such patterns that can coexist (ie , the stoichiometry) in full complements of (p^N + 1) MUBs. We consider Hilbert spaces of prime power dimension (as realized by systems of N prime-state particles, or qupits), where full complements are known to exist, and we assume only that MUBs are eigenbases of generalized Pauli operators, without using a particular construction. The general rules include the following: 1) In any MUB, a particular qupit appears either in a pure …

~115 Gev And ~143 Gev Higgs Mass Considerations Within The Composite Particles Model, Marko Popovic

Marko B. Popovic

The radiatively generated Higgs mass is obtained by requiring that leading “divergences” are cancelled in both 2D and 4D. This predicts that the k=1 mode mass is ݉ ு ≅ ଶ ଷ݉ ௧ ؆ ͳͳͷܩܸ݁ whereas the k=2 mode is ؆ ͳͶ͵ ܩܸ݁. These findings are interpreted within the Composite Particles Model (CPM), [Popovic 2002, 2010], with the massive top quark being a baryon-like structure composed of 3 fundamental О quarks and the massive Higgs scalar being a color-neutral meson like structure composed of 2 fundamental О quarks. The CPM predicts that the Z mass generation is mediated primarily by …

Critical Slowing Down In Polynomial Time Algorithms, Alan Middleton

Physics - All Scholarship

Combinatorial optimization algorithms which compute exact ground state configurations in disordered magnets are seen to exhibit critical slowing down at zero temperature phase transitions. Using arguments based on the physical picture of the model, including vanishing stiffness on scales beyond the correlation length and the ground state degeneracy, the number of operations carried out by one such algorithm, the push-relabel algorithm for the random field Ising model, can be estimated. Some scaling can also be predicted for the 2D spin glass.

The Evolution Of Stellar Structures In Dwarf Galaxies, N. Bastian, D. R. Weisz, E. D. Skillman, K.B. W. Mcquinn, A. E. Dolphin, R. A. Gutermuth, John M. Cannon, B. Ercolano, M. Gieles, R. C. Kennicutt, F. Walter

John Cannon

No abstract provided.

Turbulent Mixing And Layer Formation In Double-Diffusive Convection: 3d Numerical Simulations And Theory, Erica Rosenblum, Pascale Garaud, Adrienne L. Traxler, Stephan Stellmach

Physics Faculty Publications

Double-diffusive convection, often referred to as semi-convection in astrophysics, occurs in thermally and compositionally stratified systems which are stable according to the Ledoux criterion but unstable according to the Schwarzschild criterion. This process has been given relatively little attention so far, and its properties remain poorly constrained. In this paper, we present and analyze a set of three-dimensional simulations of this phenomenon in a Cartesian domain under the Boussinesq approximation. We find that in some cases the double-diffusive convection saturates into a state of homogeneous turbulence, but with turbulent fluxes several orders of magnitude smaller than those expected from direct …

Particle Tracking And Aod Control, Nathaniel Wolanyk, Carl Mueller, Patrick Dahl, Evan Baker, Gabriel Spalding, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Rotational Properties Of Trojan Asteroid 5209, Daniel Larocca, Linda French, Faculty Advisor

John Wesley Powell Student Research Conference

We present VR photometric observations of several Trojan asteroids and of asteroid 5209 1 989 CW1. Trojan Asteroids are found in the L4 and L5 stable Lagrange points of Jupiter's orbit. These asteroids are farther away and generally more dim than Main Belt asteroids and have received less attention from observers in the past. By plotting the lightcurve of the asteroid, we were able to determine the rotation period and the lightcurve amplitude. The goal of this research is to eventually understand the collision history of the Trojan asteroids and to compare the asteroids to those in the Main Belt. …

Creating A Simple Open Source Matlab Program Used To Control Adaptive Optics, Evan Baker, Carl Mueller, Patrick Dahl, Nathanial Wolanyk, Gabriel Spalding, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Comparison Of Aberration Correction Methodologies, Patrick Dahl, Carl Mueller, Nathanial Wolanyk, Evan Baker, Gabriel Spalding, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Ir Astrometry And Photometry Of The Abell 1882 Supergroup, Derrick Rohl, Linda French, Faculty Advisor, Percy Gomez, Faculty Advisor

John Wesley Powell Student Research Conference

Previously observed characteristics of the Abell 1 882 supergroup show signs of early stages of cluster formation. Supergroups and clusters have already been studied, but the unique stage of Abell 1 882 will aid in understanding the process of galaxy cluster formation. The data set contains observations from the Infrared Side Port Imager at the 4.0-m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) during May 2010. The data reduction process, unique challenges of working with infrared data, and preliminary results will be discussed.

Rohl worked with Gomez from January through March 201 1 as a research assistant with …

The Efficacy Of Galaxy Shape Parameters In Photometric Redshift Estimation: A Neural Network Approach, Jack Singal, M. Shmakova, B. Gerke, R. L. Griffith, J. Lotz

Physics Faculty Publications

We present a determination of the effects of including galaxy morphological parameters in photometric redshift estimation with an artificial neural network method. Neural networks, which recognize patterns in the information content of data in an unbiased way, can be a useful estimator of the additional information contained in extra parameters, such as those describing morphology, if the input data are treated on an equal footing. We use imaging and five band photometric magnitudes from the All-wavelength Extended Groth Strip International Survey. It is shown that certain principal components of the morphology information are correlated with galaxy type. However, we find …

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Mictrogravity, Troy Munro, Heng Ban

Presentations

No abstract provided.

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Microgravity, Troy Munro, Heng Ban, Jr Dennison

Presentations

No abstract provided.

Specificity, Transfer, And The Development Of Expertise, David T. Brookes, Brian H. Ross, Jose P. Mestre

Department of Physics

In this paper we present the results of two experiments designed to understand how physics students’ learning of the concept of refraction is influenced by the cognitive phenomenon of ‘‘specificity.’’ In both experiments participants learned why light bends as it travels from one optical medium to another with an analogy made to a car driving from paved road into mud and vice versa. They then learned how to qualitatively draw the direction of refracted light rays with an example of a glass prism. One group learned with a rectangular prism example while a second group learned with a triangular prism …

Thermodynamics, Hydrodynamics And Critical Phenomena In Strongly Coupled Gauge Theories, Christopher Pagnutti

Electronic Thesis and Dissertation Repository

The gauge theory / string theory correspondence has led to great progress in the study of strongly-coupled gauge theories. In this work, we start with a detailed treatment of some simple examples of this correspondence in order to establish some of the concepts and techniques are used on a more complicated system. We then consider a (3+1)-dimensional theory of gravity with a translationally invariant horizon, that is assumed to be dual to a (2+1)-dimensional non-conformal gauge theory at finite temperature. We study the thermodynamics of this model and find that there exists an exotic type of second-order phase transition wherein …

Oxygen Vacancies Adjacent To Cu(2+) Ions In Tio(2) (Rutile) Crystals, A. T. Brant, Shan Yang (杨山), Nancy C. Giles, Zafar Iqbal, A. Manivannan, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to characterize Cu²⁺ ions substituting for Ti⁴⁺ ions in nominally undoped TiO₂ crystals having the rutile structure. Illumination at 25 K with 442 nm laser light reduces the concentration of Cu²⁺ ions by more than a factor of 2. The laser light also reduces the EPR signals from Fe³⁺ and Cr³⁺ ions and introduces signals from Ti³⁺ ions. Warming in the dark to room temperature restores the crystal to its preilluminated state. Monitoring the recovery of the photoinduced changes in the Cu …

Characterization Of Continuous Vacuum Ultraviolet Lamps-Implication On The Study Of Methane Photolysis At Lyman Alpha (121.6 Nm), M-C. Gazeau, Y. Benilan, Et. Es-Sebbar, A. Jolly, E. Arzoumanian, N. Fray, H. Cottin

Dr. Et-touhami Es-sebbar

Low-temperature hydrogen plasmas are widely used as continuous vacuum ultraviolet irradiation sources in photochemical studies and, in particular, in laboratory simulations of planetary atmospheres. One of the most challenging objectives of such experiments is to retrieve accurate quantitative laboratory data allowing a reliable comparison with theoretical and/or observational ones. This task can only be achieved when the irradiation source delivers a well characterised radiation in terms of flux and wavelength dependency. As an example, we will present a study, developed in the frame of a program dedicated to simulations of Titan’s atmosphere, on methane photolysis at Lyman alpha (121.6 nm). …

Formation Of Hcn And Nh3 As Primary Compounds Of Titan’S Atmosphere Simulations Using N2-Ch4 Afterglow Plasma’’, M-C. Gazeau, Y. Bénilan, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, C.D. Pintassilgo

Dr. Et-touhami Es-sebbar

No abstract provided.

Language Discourse- A Critical Analysis Of Michel Focault's Work On Language Discourse With Special Reference To His Masterpiece "The Archeology Of Knowledge", Ratnesh Dwivedi Mr

Ratnesh Dwivedi

Discourse generally refers to "written or spoken communication or debate". The following are three more specific definitions: (1) In semantics and discourse analysis: A generalization of the concept of conversation to all modalities and contexts. (2) "The totality of codified linguistic usages attached to a given type of social practice. (E.g.: legal discourse, medical discourse, religious discourse.)" (3) In the work of Michel Foucault, and social theorists inspired by him: "an entity of sequences of signs in that they are enouncements (enoncés)" (Foucault 1969: 141). An enouncement (often translated as "statement") is not a unity of signs, but an abstract …