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Some Aspects of Reactor Theory

Description: Report that outlines the major issue of reactor theory and asymptotic reactor theory. Uncommon reactor theory results are also discussed and unanswered questions regarding reactor theory are presented by the author.
Date: October 10, 1952
Creator: Weinberg, Alvin Martin
Partner: UNT Libraries Government Documents Department

Dynamics of N = 2 Supersymmetric Gauge Theories in Three Dimensions

Description: We study the structure of the moduli spaces of vacua and superpotentials of N = 2 supersymmetric gauge theories in three dimensions. By analyzing the instanton corrections, we compute the exact superpotentials and determine the quantum Coulomb and Higgs branches of the theories in the weak coupling regions. We find candidates for non-trivial N = 2 superconformal field theories at the singularities of the moduli spaces. The analysis is carried out explicitly for gauge groups U(N{sub c}) and SU(N{sub c}) with N{sub f} flavors. We show that the field theory results are in complete agreement with the intersecting branes picture. We also compute the exact superpotentials for arbitrary gauge groups and arbitrary matter content.
Date: March 21, 1997
Creator: de Boer, J.; Hori, K. & Oz, Y.
Partner: UNT Libraries Government Documents Department

Note on the Theorems of Bjerknes and Crocco

Description: "The theorems of Bjerknes and Crocco are of great interest in the theory of flow around airfoils at Mach numbers near and above unity. A brief note shows how both theorems are developed by short vector transformations" (p. 1).
Date: May 1946
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

Field Theory On the World Sheet: Mean Field Expansion And Cutoff Dependence

Description: Continuing earlier work, we apply the mean field method to the world sheet representation of a simple field theory. In particular, we study the higher order terms in the mean field expansion, and show that their cutoff dependence can be absorbed into a running coupling constant. The coupling constant runs towards zero in the infrared, and the model tends towards a free string. One cannot fully reach this limit because of infrared problems, however, one can still apply the mean field method to the high energy limit (high mass states) of the string.
Date: January 10, 2007
Creator: Bardakci, Korkut
Partner: UNT Libraries Government Documents Department

The Evolution of Capital Formation Theory

Description: The various aspects of a social science ramify closely with one another, and so it will be necessary to inspect certain economic theories rather extensively in search of their meaningful connection with the word "capital." However, the major purpose here will be an examination of the use and potential logical use of the terms "capital" and "capital formation."
Date: August 1962
Creator: Hodgson, Richard Corrin
Partner: UNT Libraries

Diffeomorphism groups and anyon fields

Description: We make use of unitary representations of the group of diffeomorphisms of the plane to construct an explicit field theory of anyons. The resulting anyon fields satisfy q-commutators, where q is the well-known phase shift associated with a single counterclockwise exchange of a pair of anyons. Our method uses a realization of the braid group by means of paths in the plane, that transform naturally under diffeomorphisms of R{sup 2}.
Date: September 1, 1995
Creator: Goldin, G.A. & Sharp, D.H.
Partner: UNT Libraries Government Documents Department

Massive Supergravity and Deconstruction

Description: We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting Lagrangian using goldstone superfields. We find that achiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (Mpl) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (Mpl m^4)^1/5, where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various quantum effects which generate non-local operators in theory space. As an example, we show that the single massive supergravity multiplet in a 2-site model can serve the function of an extra dimension in anomaly mediation.
Date: March 23, 2004
Creator: Gregoire, Thomas; Schwartz, Matthew D. & Shadmi, Yael
Partner: UNT Libraries Government Documents Department

Comments on Cosmic Censorship in AdS/CFT

Description: Recently Hertog, Horowitz, and Maeda (HHM) (hep-th/0310054) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results (hep-th/0402109). For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS_5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS_3 example that may well be free of this instability.
Date: March 21, 2004
Creator: Hubeny, Veronika E.; Liu, Xiao; Rangamani, Mukund & Shenker, Stephen
Partner: UNT Libraries Government Documents Department

Noncommutative Dipole Field Theories And Unitarity

Description: We extend the argument of Gomis and Mehen for violation of unitarity in field theories with space-time noncommutativity to dipole field theories. In dipole field theories with a timelike dipole vector, we present 1-loop amplitudes that violate the optical theorem. A quantum mechanical system with nonlocal potential of finite extent in time also shows violation of unitarity.
Date: October 24, 2003
Creator: Chiou, Dah-Wei & Ganor, Ori J.
Partner: UNT Libraries Government Documents Department

Colliding with a crunching bubble

Description: In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.
Date: March 26, 2007
Creator: Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T. & Shenker, Stephen
Partner: UNT Libraries Government Documents Department

Supersymmetry and Superstring Phenomenology

Description: We briefly cover the early history of supersymmetry, describe the relation of SUSY quantum field theories to superstring theories and explain why they are considered a likely tool to describe the phenomenology of high energy particle theory beyond the Standard Model.
Date: May 5, 2008
Creator: Gaillard, Mary K; Gaillard, Mary K. & Zumino, Bruno
Partner: UNT Libraries Government Documents Department

Simplified Model of Nonlinear Landau Damping

Description: The nonlinear interaction of a plasma wave with resonant electrons results in a plateau in the electron distribution function close to the phase velocity of the plasma wave. As a result, Landau damping of the plasma wave vanishes and the resonant frequency of the plasma wave downshifts. However, this simple picture is invalid when the external driving force changes the plasma wave fast enough so that the plateau cannot be fully developed. A new model to describe amplification of the plasma wave including the saturation of Landau damping and the nonlinear frequency shift is proposed. The proposed model takes into account the change of the plasma wave amplitude and describes saturation of the Landau damping rate in terms of a single fluid equation, which simplifies the description of the inherently kinetic nature of Landau damping. A proposed fluid model, incorporating these simplifications, is verified numerically using a kinetic Vlasov code.
Date: July 16, 2009
Creator: Fisch, N. A. Yampolsky and N. J.
Partner: UNT Libraries Government Documents Department

Infrared Studies of Group VIB metal Carbonyl Derivatives

Description: With three different proposals for the bonding in metal carbonyls, it was decided to look into the situation more thoroughly in order to see what other evidence was available to support or refute any of these ideas. It became obvious that a definite contradiction existed between the kinetic evidence of various metal carbonyls, and the concept of MC bond strengths as predicted by Cotton's theory.
Date: August 1971
Creator: Brown, Richard Arthur
Partner: UNT Libraries