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Full-Text Articles in Physics
Inhomogeneous Fragmentation Of The Rolling Tachyon, Gary Felder, Lev Kofman
Inhomogeneous Fragmentation Of The Rolling Tachyon, Gary Felder, Lev Kofman
Physics: Faculty Publications
Dirac-Born-Infeld type effective actions reproduce many aspects of string theory classical tachyon dynamics of unstable Dp-branes. The inhomogeneous tachyon field rolling from the top of its potential forms topological defects of lower codimensions. In between them, as we show, the tachyon energy density fragments into a p-dimensional web-like high density network evolving with time. We present an analytic asymptotic series solution of the non-linear equations for the inhomogeneous tachyon and its stress energy. The generic solution for a tachyon field with a runaway potential in arbitrary dimensions is described by the free streaming of noninteracting massive particles whose initial velocities …
Braneworld Dynamics With The Branecode, Martin Johannes, Gary Felder, Andrei V. Frolov, Marco Peloso, Lev Kofman
Braneworld Dynamics With The Branecode, Martin Johannes, Gary Felder, Andrei V. Frolov, Marco Peloso, Lev Kofman
Physics: Faculty Publications
We give a full nonlinear numerical treatment of time-dependent 5D braneworld geometry, which is determined self-consistently by potentials for the scalar field in the bulk and at two orbifold branes, supplemented by boundary conditions at the branes. We describe the BRANECODE, an algorithm which we designed to solve the dynamical equations numerically. We apply the BRANECODE to braneworld models and find several novel phenomena of the brane dynamics. Starting with static warped geometry with de Sitter branes, we find numerically that this configuration is often unstable due to a tachyonic mass of the radion during inflation. If the model admits …
Critical Dynamics Of Superconductors In The Charged Regime, Courtney Lannert, Smitha Vishveshwara, Matthew P.A. Fisher
Critical Dynamics Of Superconductors In The Charged Regime, Courtney Lannert, Smitha Vishveshwara, Matthew P.A. Fisher
Physics: Faculty Publications
The charged regime of the superconductor-metal transition was analyzed by applying a finite temperature critical dynamics. A transverse gage field coupling was applied to the superconducting order parameter. A new dynamic universality class characeterized by a finite fixed point ratio between the transport coefficients associated with the order parameter and gage fields was found by assuming relaxational dynamics for both the order parameter and gage fields within a renormalization group scheme. It was found that various features of the dynamic universality class of the charged superconductor appeared in measurable quantities.
A Demonstration Of Phonons That Implements The Linear Theory, Dietrich Lüerßen, Nalini Easwar, Ayesha Malhotra, Libby Hutchins, Kim Schulze, Brandi Wilcox
A Demonstration Of Phonons That Implements The Linear Theory, Dietrich Lüerßen, Nalini Easwar, Ayesha Malhotra, Libby Hutchins, Kim Schulze, Brandi Wilcox
Physics: Faculty Publications
Beads on a vibrating wire are used to simulate the discrete structure of a solid-state material. The novel idea of the experiment is to use very small oscillation amplitudes of the wire to avoid nonlinearities in the interaction. We achieve a good signal-to-noise ratio using a lock-in technique. We find quantitative agreement between theory and experiment for not only a mono- and a diatomic chain, but also for the bare wire. The latter agreement is the crucial aspect that distinguishes our experiment from previous ones. This agreement assures that the fundamental assumption of the theory ~Hooke’s law! is satisfied. We …