Symmetry Nonrestoration at High Temperature in Little Higgs Models

A detailed study of the high temperature dynamics of the scalar sector of Little Higgs scenarios, proposed to stabilize the electroweak scale, shows that the electroweak gauge symmetry remains broken even at temperatures much larger than the electroweak scale. Although we give explicit results for a particular modification of the Littlest Higgs model, we expect that the main features are generic. As a spin-off, we introduce a novel way of dealing with scalar fluctuations in nonlinear sigma models, which might be of interest for phenomenological applications.Comment: 23 pages, LaTeX, 4 figure

Moving embedded lattice solitons

It was recently proved that isolated unstable "embedded lattice solitons" (ELS) may exist in discrete systems. The discovery of these ELS gives rise to relevant questions such as the following: are there continuous families of ELS?, can ELS be stable?, is it possible for ELS to move along the lattice?, how do ELS interact?. The present work addresses these questions by showing that a novel differential-difference equation (a discrete version of a complex mKdV equation) has a two-parameter continuous family of exact ELS. The numerical tests reveal that these solitons are stable and robust enough to withstand collisions. The model may apply to the description of a Bose-Einstein condensate with dipole-dipole interactions between the atoms, trapped in a deep optical-lattice potential.Comment: 13 pages, 11 figure

Berry's phase in noncommutative spaces

We introduce the perturbative aspects of noncommutative quantum mechanics. Then we study the Berry's phase in the framework of noncommutative quantum mechanics. The results show deviations from the usual quantum mechanics which depend on the parameter of space/space noncommtativity.Comment: 7 pages, no figur

Complete two-loop effective potential approximation to the lightest Higgs scalar boson mass in supersymmetry

I present a method for accurately calculating the pole mass of the lightest Higgs scalar boson in supersymmetric extensions of the Standard Model, using a mass-independent renormalization scheme. The Higgs scalar self-energies are approximated by supplementing the exact one-loop results with the second derivatives of the complete two-loop effective potential in Landau gauge. I discuss the dependence of this approximation on the choice of renormalization scale, and note the existence of particularly poor choices which fortunately can be easily identified and avoided. For typical input parameters, the variation in the calculated Higgs mass over a wide range of renormalization scales is found to be of order a few hundred MeV or less, and is significantly improved over previous approximations.Comment: 5 pages, 1 figure. References added, sample test model parameters listed, minor wording change

Heisenberg quantization for the systems of identical particles and the Pauli exclusion principle in noncommutative spaces

We study the Heisenberg quantization for the systems of identical particles in noncommtative spaces. We get fermions and bosons as a special cases of our argument, in the same way as commutative case and therefore we conclude that the Pauli exclusion principle is also valid in noncommutative spaces.Comment: 8 pages, 1 figur

Towards a Media Interpretation Framework for the Semantic Web

We present a framework for media interpretation that leverages low-level information extraction to a higher level of abstraction in order to support semantics-based information retrieval for the Semantic Web. The overall goal of the framework is to provide high-level content descriptions of documents for maximizing precision and recall of semantics-based information retrieval

So close, no matter how far: A spatial analysis of CO2 emissions considering geographic and economic distances

In recent years, the effects of climate change have become a topic of growing interest in the literature. Many works claimed the importance of spillover effects while studying CO2 emissions. Most part of them considers these indirect effects from a geographical perspective. The reduction of transportation costs makes other factors more important. Thus, the main aim of this paper is to analyse the existence of spatial dependence, considering geographical and economic proximity and comparing both measures. Empirically, we make use of the World Input–Output database with a worldwide focus from 2000 to 2014. Based on an environmentally extended multiregional input–output model, we estimate the CO2 emissions embodied in the domestic production and international trade between countries. To analyse the dependence from both perspectives, we carry out a spatial econometric analysis and make use of two different spatial weight matrices. The results offer a new approach on this field, highlighting the importance of the spillover effects to explain the CO2 emissions of the local country, showing that economic proximity is even more important than geographical one