Non-commutative holonomies in 2+1 LQG and Kauffman's brackets

We investigate the canonical quantization of 2+1 gravity with {\Lambda} > 0 in the canonical framework of LQG. A natural regularization of the constraints of 2+1 gravity can be defined in terms of the holonomies of A\pm = A \PM \surd{\Lambda}e, where the SU(2) connection A and the triad field e are the conjugated variables of the theory. As a first step towards the quantization of these constraints we study the canonical quantization of the holonomy of the connection A_{\lambda} = A + {\lambda}e acting on spin network links of the kinematical Hilbert space of LQG. We provide an explicit construction of the quantum holonomy operator, exhibiting a close relationship between the action of the quantum holonomy at a crossing and Kauffman's q-deformed crossing identity. The crucial difference is that the result is completely described in terms of standard SU(2) spin network states.Comment: 4 pages; Proceedings of Loops'11, Madrid, to appear in Journal of Physics: Conference Series (JPCS

Background and principle applications of remote sensing in Mexico

Remote sensing, or the collection of information from objectives at a distance, crystallizes the interest in implementing techniques which assist in the search for solutions to the problems raised by the detection, exploitation, and conservation of the natural resources of the earth. An attempt is made to present an overview of the studies and achievements which have been obtained with remote sensing in Mexico

Quantum computational tensor network on string-net condensate

The string-net condensate is a new class of materials which exhibits the quantum topological order. In order to answer the important question, "how useful is the string-net condensate in quantum information processing?", we consider the most basic example of the string-net condensate, namely the $Z_2$ gauge string-net condensate on the two-dimensional hexagonal lattice, and show that the universal measurement-based quantum computation (in the sense of the quantum computational webs) is possible on it by using the framework of the quantum computational tensor network. This result implies that even the most basic example of the string-net condensate is equipped with the correlation space that has the capacity for the universal quantum computation.Comment: 5 pages, 4 figure

Asymmetries in top quark pair production at hadron colliders

We review the asymmetries in top quark pair production at the Tevatron and the LHC. We summarize the experimental measurements and the interpretations of a possible excess in terms of new physics. We also review other top quark properties-emphasizing effects related to the $t \bar t$ asymmetries-as well as other collider signals.Comment: RevTeX 40 pages. Final version to be published in Reviews of Modern Physics, with several addition

Constraints on the braneworld from compact stars

According to the braneworld idea, ordinary matter is confined on a 3-dimensional space (brane) that is embedded in a higher-dimensional space-time where gravity propagates. In this work, after reviewing the limits coming from general relativity, finiteness of pressure and causality on the brane, we derive observational constraints on the braneworld parameters from the existence of stable compact stars. The analysis is carried out by solving numerically the brane-modified Tolman-Oppenheimer-Volkoff equations, using different representative equations of state to describe matter in the star interior. The cases of normal dense matter, pure quark matter and hybrid matter are considered.Comment: 13 pages, 11 figures, 2 tables; new EoS considered, references and comments adde