Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication
- Publication Type
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou
Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou
Physics Faculty Publications
Explorations of the violation of null energy condition (NEC) in cosmology could enrich our understanding of the very early universe and the related gravity theories. Although a fully stable NEC violation can be realized in the “beyond Horndeski” theory, it remains an open question whether a violation of the NEC is allowed by some fundamental properties of UV-complete theories or the consistency requirements of effective field theory (EFT). We investigate the tree-level perturbative unitarity for stable NEC violations in the contexts of both Galileon and “beyond Horndeski” genesis cosmology, in which the universe is asymptotically Minkowskian in the past. We …
Particle Dynamics In Anti-De Sitter Space By Eih Method, Jiusi Lei
Particle Dynamics In Anti-De Sitter Space By Eih Method, Jiusi Lei
Dissertations, Theses, and Capstone Projects
Following the work of Einstein, Infeld and Hoffmann, we show that particle dynamics in Anti-de Sitter spacetime can be built up by regarding singularities in spacetime manifold as the source of particles.
Since gauge fields play a foundational role in the action, the singularities are chosen to be point-like instantons. Their winding number, defined by an integration on the spheres surrounding those singularities, will turn out to be related to their masses. And their action, derived from the Chern-Simons forms, will be a co-adjoint orbit action, with group element g ∈ SO(4, 2) describing the collective coordinates of the particle. …
Unification Of Gravity And Quantum Theory, Adam Daniels
Unification Of Gravity And Quantum Theory, Adam Daniels
Faculty-Sponsored Student Research & Capstones
An overview of the four fundamental forces of physics as described by the Standard Model (SM) and prevalent unifying theories beyond it is provided. Background knowledge of the particles governing the fundamental forces is provided, as it will be useful in understanding the way in which the unification efforts of particle physics has evolved, either from the SM, or apart from it. It is shown that efforts to provide a quantum theory of gravity have allowed supersymmetry (SUSY) and M-Theory to become two of the prevailing theories for unifying gravity with the remaining non-gravitational forces.
New Classical Solutions In Supergravity, Zhibai Zhang
New Classical Solutions In Supergravity, Zhibai Zhang
Dissertations, Theses, and Capstone Projects
In this Ph.D. thesis we construct three classes of new solutions to supergravity theories in various dimensions and study their properties. The first class is reduction ansatz of 10D and 11D supergravity on Ricci-flat and noncompact manifolds. These reductions are from a scaling limit of the famous spherical reductions, and can be solely supported by warp factors. The second class contains a large number of String/M theory solutions that have Lifshitz or Schrodinger scaling symmetry, obtained from marginally deforming the geometry of internal dimensions of previous solutions. We propose that these new solutions are dual to marginal deformations of certain …
The Spacetime Co-Torsion In Torsion-Free Biconformal Spaces, James Thomas Wheeler
The Spacetime Co-Torsion In Torsion-Free Biconformal Spaces, James Thomas Wheeler
James Thomas Wheeler
In preceding studies, [TR Gamma minus, TR Gamma plus] we showed that the solution for the connection of flat biconformal space also solves the curved space field equations for the torsion and co-torsion. We continued this investigation with an attempt to solve the full set of torsion and co-torsion field equations, with only the assumption of vanishing torsion and the known form of the metric. We successfully reduced the torsion equations to a single equation. Here, we reduce that equation to its essential degrees of freedom. We find that the spacetime co-torsion is entirely determined by the scale vector and …
Studies In Torsion Free Biconformal Spaces, James Thomas Wheeler
Studies In Torsion Free Biconformal Spaces, James Thomas Wheeler
All Physics Faculty Publications
We study whether the solutions for the symmetric part of the connection in homogeneous biconformal space also satisfy the more general field equation of curved biconformal spaces. We show that the six field equations for the torsion and co-torsion are satisfied by vanishing torsion together with the Lorentzian form of the metric when γ+ = 0.
Gauge Transformations Of The Biconformal Connection, James Thomas Wheeler
Gauge Transformations Of The Biconformal Connection, James Thomas Wheeler
All Physics Faculty Publications
We study the changes of the biconformal gauge fields under the local rotational and dilatational gauge transformations.
Condensed Matter From Gauge/Gravity Duality, Jason Edward Therrien
Condensed Matter From Gauge/Gravity Duality, Jason Edward Therrien
Doctoral Dissertations
Currently strongly coupled systems present the greatest challenge to theoretical physics. For years conventional methods of approach have failed to describe these systems analytically. In recent years it has been shown that there is a duality between weakly coupled and strongly coupled systems, the Gauge Theory/Gravity Duality. In this dissertation I will discuss how the AdS/CFT is used to describe strongly coupled condensed matter systems as well as present the work done by the author and collaborators.