Baryogenesis from Unstable Domain Walls

There exists a class of cosmic strings that turn matter into antimatter (Alice strings). In a GUT where the unbroken gauge group contains charge conjugation ($C$), such strings form when a phase transition renders $C$ a discrete symmetry. They become boundaries of domain walls at a later, $C$-breaking transition. These `Alice walls' are cosmologically harmless, but can play an important role in baryogenesis. We present a three-generation toy model with scalar baryons, where a quasi-static Alice wall (or a gas of such walls) temporarily gives rise to net baryogenesis of uniform sign everywhere in space. This becomes a permanent baryon excess if the wall shrinks away early enough. We comment on the possible relevance of a similar mechanism to baryogenesis in a realistic \soten unification model, where Alice walls would form at the scale of left-right symmetry breaking.Comment: SLAC-PUB-5828, May 92. 28 pp. Seven figures (not included). Use PHYZZ

Superconductivity Solves the Monopole Problem for Alice Strings

Alice strings are cosmic strings that turn matter into antimatter. Although they arise naturally in many GUT's, it has long been believed that because of the monopole problem they can have no cosmological effects. We show this conclusion to be false; by using the Langacker-Pi mechanism, monopoles can in fact be annihilated while Alice strings are left intact. This opens up the possibility that they can after all contribute to cosmology, and we mention some particularly important examples.Comment: 16 pages, 7 figures (not included

Using Annual Panel Data To Examine The Monday Effect

The Monday effect is a well-known anomaly in which Monday stocks returns are significantly different from other days. Recent research suggests that small-cap stocks exhibit negative and significant Monday returns, mid-cap stocks show no Monday effect and large-cap stocks have positive and significant Monday returns. In this short paper we re-examine the Monday effect using a somewhat different approach that the rest of the literature. Specifically, we examine the U.S. mean Monday returns for each market capitalization decile and for each year over the period 1966-2007. We then examine the patterns of these annual Monday returns. Using this method, we find that the Monday effect has dissipated for all sizes of stocks so much that, by the middle 1990s, the Monday returns are generally not significant from zero

Self-Gravitating Strings In 2+1 Dimensions

We present a family of classical spacetimes in 2+1 dimensions. Such a spacetime is produced by a Nambu-Goto self-gravitating string. Due to the special properties of three-dimensional gravity, the metric is completely described as a Minkowski space with two identified worldsheets. In the flat limit, the standard string is recovered. The formalism is developed for an open string with massive endpoints, but applies to other boundary conditions as well. We consider another limit, where the string tension vanishes in geometrical units but the end-masses produce finite deficit angles. In this limit, our open string reduces to the free-masses solution of Gott, which possesses closed timelike curves when the relative motion of the two masses is sufficiently rapid. We discuss the possible causal structures of our spacetimes in other regimes. It is shown that the induced worldsheet Liouville mode obeys ({\it classically}) a differential equation, similar to the Liouville equation and reducing to it in the flat limit. A quadratic action formulation of this system is presented. The possibility and significance of quantizing the self-gravitating string, is discussed.Comment: 55 page

Interaction potential in compact three-dimensional QED with mixed action

We use a variational wave function to calculate the energy of the interaction between external charges in the compact Abelian gauge theory in 2+1 dimensions with mixed action. Our variational wave functions preserve the compact gauge invariance of the theory both in the vacuum and in the charged sectors. We find that a good estimate of the interaction energy is obtained only when we allow more variational parameters in the charged sector than in the vacuum sector. These extra parameters are the profile of an induced electric field. We find that the theory has a two-phase structure: When the charge-2 coupling is large and negative there is no mass gap in the theory and no confinement, while otherwise a mass gap is generated dynamically and the theory confines charges. The pure Wilson theory is in the confining phase.Comment: 22 pages, Latex -- final version, minor changes from first versio

Leptogenesis with Left-Right domain walls

The presence of domain walls separating regions of unbroken $SU(2)_L$ and $SU(2)_R$ is shown to provide necessary conditions for leptogenesis which converts later to the observed Baryon aymmetry. The strength of lepton number violation is related to the majorana neutrino mass and hence related to current bounds on light neutrino masses. Thus the observed neutrino masses and the Baryon asymmetry can be used to constrain the scale of Left-Right symmetry breaking.Comment: References added, To appear in Praman

CORE Technology and Exact Hamiltonian Real-Space Renormalization Group Transformations

The COntractor REnormalization group (CORE) method, a new approach to solving Hamiltonian lattice systems, is presented. The method defines a systematic and nonperturbative means of implementing Kadanoff-Wilson real-space renormalization group transformations using cluster expansion and contraction techniques. We illustrate the approach and demonstrate its effectiveness using scalar field theory, the Heisenberg antiferromagnetic chain, and the anisotropic Ising chain. Future applications to the Hubbard and t-J models and lattice gauge theory are discussed.Comment: 65 pages, 9 Postscript figures, uses epsf.st

Can Light Signals Travel Faster than c in Nontrivial Vacuua in Flat space-time? Relativistic Causality II

In this paper we show that the Scharnhorst effect (Vacuum with boundaries or a Casimir type vacuum) cannot be used to generate signals showing measurable faster-than-c speeds. Furthermore, we aim to show that the Scharnhorst effect would violate special relativity, by allowing for a variable speed of light in vacuum, unless one can specify a small invariant length scale. This invariant length scale would be agreed upon by all inertial observers. We hypothesize the approximate scale of the invariant length.Comment: 12 pages no figure

Water waves generated by a moving bottom

Tsunamis are often generated by a moving sea bottom. This paper deals with the case where the tsunami source is an earthquake. The linearized water-wave equations are solved analytically for various sea bottom motions. Numerical results based on the analytical solutions are shown for the free-surface profiles, the horizontal and vertical velocities as well as the bottom pressure.Comment: 41 pages, 13 figures. Accepted for publication in a book: "Tsunami and Nonlinear Waves", Kundu, Anjan (Editor), Springer 2007, Approx. 325 p., 170 illus., Hardcover, ISBN: 978-3-540-71255-8, available: May 200

Transient domain walls and lepton asymmetry in the Left-Right symmetric model

It is shown that the dynamics of domain walls in Left-Right symmetric models, separating respective regions of unbroken SU(2)_L and SU(2)_R in the early universe, can give rise to baryogenesis via leptogenesis. Neutrinos have a spatially varying complex mass matrix due to CP-violating scalar condensates in the domain wall. The motion of the wall through the plasma generates a flux of lepton number across the wall which is converted to a lepton asymmetry by helicity-flipping scatterings. Subsequent processing of the lepton excess by sphalerons results in the observed baryon asymmetry, for a range of parameters in Left-Right symmetric models.Comment: v2 version accepted for publication in Phys. Rev. D. Discussion in Introduction and Conclusion sharpened. Equation (12) corrected. 16 pages, 3 figure files, RevTeX4 styl