Fermion Masses from SO(10) Hermitian Matrices

Masses of fermions in the SO(10) 16-plet are constructed using only the 10, 120 and 126 scalar multiplets. The mass matrices are restricted to be hermitian and the theory is constructed to have certain assumed quark masses, charged lepton masses and CKM matrix in accord with data. The remaining free parameters are found by fitting to light neutrino masses and MSN matrices result as predictions.Comment: 23 pages. Small textual additions for clarification; formalism and results unchanged. Version to appear in Phys. Rev.

Regularization of fields for self-force problems in curved spacetime: foundations and a time-domain application

We propose an approach for the calculation of self-forces, energy fluxes and waveforms arising from moving point charges in curved spacetimes. As opposed to mode-sum schemes that regularize the self-force derived from the singular retarded field, this approach regularizes the retarded field itself. The singular part of the retarded field is first analytically identified and removed, yielding a finite, differentiable remainder from which the self-force is easily calculated. This regular remainder solves a wave equation which enjoys the benefit of having a non-singular source. Solving this wave equation for the remainder completely avoids the calculation of the singular retarded field along with the attendant difficulties associated with numerically modeling a delta function source. From this differentiable remainder one may compute the self-force, the energy flux, and also a waveform which reflects the effects of the self-force. As a test of principle, we implement this method using a 4th-order (1+1) code, and calculate the self-force for the simple case of a scalar charge moving in a circular orbit around a Schwarzschild black hole. We achieve agreement with frequency-domain results to ~ 0.1% or better.Comment: 15 pages, 12 figures, 1 table. More figures, extended summar

Electronic Structure of Hyperkagome Na4Ir3O8

We investigate the electronic structure of the frustrated magnet Na4Ir3O8 using density functional theory. Due to strong spin-orbit coupling, the hyperkagome lattice is characterized by a half-filled complex of states, making it a cubic iridium analogue of the high temperature superconducting cuprates. The implications of our results for this unique material are discussed.Comment: expanded discussion with extra figures - 6 pages, 10 figure

Spin Hamiltonian of Hyperkagome Na4Ir3O8

We derive the spin Hamiltonian for the quantum spin liquid Na4Ir3O8, and then estimate the direct and superexchange contributions between near neighbor iridium ions using a tight binding parametrization of the electronic structure. We find a magnitude of the exchange interaction comparable to experiment for a reasonable value of the on-site Coulomb repulsion. For one of the two tight binding parametrizations we have studied, the direct exchange term, which is isotropic, dominates the total exchange. This provides support for those theories proposed to describe this novel quantum spin liquid that assume an isotropic Heisenberg model.Comment: 9 pages, 4 figure

T-Shape Molecular Heat Pump

We report on the first molecular device of heat pump modeled by a T-shape Frenkel-Kontorova lattice. The system is a three-terminal device with the important feature that the heat can be pumped from the low-temperature region to the high-temperature region through the third terminal. The pumping action is achieved by applying a stochastic external force that periodically modulates the atomic temperature. The temperature, the frequency and the system size dependence of heat pump are briefly discussed.Comment: 6 figure

Scalar radiation from Chameleon-shielded regions

I study the profile of the Chameleon field around a radially pulsating mass. Focusing on the case in which the background (static) Chameleon profile exhibits a thin-shell, I add small perturbations to the source in the form of time-dependent radial pulsations. It is found that the Chameleon field inherits a time-dependence, there is a resultant scalar radiation from the region of the source and the metric outside the spherically symmetric mass is not static. This has several interesting and potentially testable consequences.Comment: 4 pages, 4 figures, slightly edited version matching the journal versio

A statistical mechanics model for free-for-all airplane passenger boarding

I present and discuss a model for the free-for-all passenger boarding which is employed by some discount air carriers. The model is based on the principles of statistical mechanics where each seat in the aircraft has an associated energy which reflects the preferences of the population of air travelers. As each passenger enters the airplane they select their seats using Boltzmann statistics, proceed to that location, load their luggage, sit down, and the partition function seen by remaining passengers is modified to reflect this fact. I discuss the various model parameters and make qualitative comparisons of this passenger boarding model with models which involve assigned seats. This model can also be used to predict the probability that certain seats will be occupied at different times during the boarding process. These results may be of value to industry professionals as a useful description of this boarding method. However, it also has significant value as a pedagogical tool since it is a relatively unusual application of undergraduate level physics and it describes a situation with which many students and faculty may be familiar.Comment: version 1: 4 pages 2 figures version 2: 7 pages with 5 figure

Phase diagram of Landau-Zener phenomena in coupled one-dimensional Bose quantum fluids

We study stationary and dynamical properties of the many-body Landau-Zener dynamics of a Bose quantum fluid confined in two coupled one-dimensional chains, using a many-body generalization recently reported [Y.-A. Chen et al.], within the decoupling approximation and the one-level band scheme. The energy spectrum evidences the structure of the avoided level crossings as a function of the on-site inter particle interaction strength. On the dynamical side, a phase diagram of the transfer efficiency across ground-state and inverse sweeps is presented. A totally different scenario with respect to the original single-particle Landau-Zener scheme is found for ground-state sweeps, in which a breakdown of the adiabatic region emerges as the sweep rate decreases. On the contrary, the transfer efficiency across inverse sweeps reveals consistent results with the single-particle Landau-Zener predictions. In the strong coupling regime, we find that there is a critical value of the on-site interaction for which the transfer of particles starts to vanish independently of the sweep rate. Our results are in qualitative agreement with those of the experimental counterpart.Comment: 15 pages, submitted to Phys. Rev. A (new version

Faraday waves in elongated superfluid fermionic clouds

We use hydrodynamic equations to study the formation of Faraday waves in a superfluid Fermi gas at zero temperature confined in a strongly elongated cigar-shaped trap. First, we treat the role of the radial density profile in the limit of an infinite cylindrical geometry and analytically evaluate the wavelength of the Faraday pattern. The effect of the axial confinement is fully taken into account in the numerical solution of hydrodynamic equations and shows that the infinite cylinder geometry provides a very good description of the phenomena.Comment: 6 pages, 7 figures. Figures 4 and 6 in high resolution on reques