U(1) Noncommutative Gauge Fields and Magnetogenesis

The connection between the Lorentz invariance violation in the lagrangean context and the quantum theory of noncommutative fields is established for the U(1) gauge field. The modified Maxwell equations coincide with other derivations obtained using different procedures. These modified equations are interpreted as describing macroscopic ones in a polarized and magnetized medium. A tiny magnetic field (seed) emerges as particular static solution that gradually increases once the modified Maxwell equations are solved as a self-consistent equations system.Comment: 4 page

Gauge Field Theory in the Infrared Regime

We propose that the low energy behavior of a pure gauge theory can be studied by simply assuming violation of Lorentz invariance which is implemented through a deformation of the canonical Poisson brackets of the theory depending on an infrared scale. The resulting theory is equivalent to a pure gauge theory with a Chern-Simons like term. It is shown that at low energies this theory can be identified with three dimensional QCD where the mass of the fermion is related to the infrared scale.Comment: 4pp, ReVte

Vortices in U(1) Noncommutative Gauge Fields

Charged vortex solutions for noncommutative Maxwell-Higgs model in 3+1 dimensions are found. We show that the stability of these vortex solutions is spoiled out for some, large enough, noncommutativity parameter. A non topological charge, however, is induced by noncommutative effects.Comment: references added, slight modifications in the introduction and conclusions. To be published in PR

SU(2) Kinetic Mixing Terms and Spontaneous Symmetry Breaking

The non-abelian generalization of the Holdom model --{\it i.e.} a theory with two gauge fields coupled to the kinetic mixing term $g {tr}(F_{\mu \nu} (A) F_{\mu \nu} (B))$-- is considered. Contrarily to the abelian case, the group structure $G\times G$ is explicitly broken to $G$. For SU(2) this fact implies that the residual gauge symmetry as well as the Lorentz symmetry is spontaneusly broken. We show that this mechanism provides of masses for the involved particles. Also, the model presents instanton solutions with a redefined coupling constant.Comment: 9pp. typos and clarifications are adde

Efecto de la sustitución catiónica y aniónica en las transiciones de fase del LiNH4SO4

El ß LÍNH4SO4 (ß LAS) presenta dos transiciones de fase, una alrededor de 10 °C y la otra a 186 °C. La fase intermedia es ferroeléctrica. En este trabajo se estudia el efecto que produce la sustitución parcial del catión amonio por rubidio y del anión sulfato por seleniato en dichas transiciones de fase. Se establece la zona de existencia de las soluciones sólidas Li(NH4)-^_^Rb^S04 y LiNH4(SO^)^_^(Se04)^ en las que se mantiene la estructura del ß LAS. La presencia de aniones seleniato o de cationes rubidio afecta a las transiciones de fase de alta y baja temperatura, por lo que, tanto los tetraedros sulfato como el catión amonio intervienen en dichas transiciones. Hay un efecto cooperativo entre el desorden de los grupos sulfato y las distorsiones de los tetraedros amonio. El mecanismo que puede explicar estas transiciones es del tipo orden-desorden

Vortices, infrared effects and Lorentz invariance violation

The Yang-Mills theory with non-commutative fields is constructed following Hamiltonian and Lagrangian methods. This modification of the standard Yang-Mills theory produces spatially localized solutions very similar to those of the standard non-Abelian gauge theories. This modification of the Yang-Mills theory contain in addition to the standard contribution, the term θμεμνρλ (Aν Fρλ + 2/3 Aν Aρ Aλ) where θμ is a given space-like constant vector with canonical dimension of energy. The Aμ field rescaling and the choice θμ=(0,0,0,θ), suggest the equivalence between the Yang-Mills-Chern-Simons theory in 2+1 dimensions and QCD in 3+1 dimensions in the heavy fermionic excitations limit. Thus, the Yang-Mills-Chern-Simons theory in 2+1 dimensions could be a codified way to QCD with only heavy quarks. The classical solutions of the modified Yang-Mills theory for the SU(2) gauge group are explicitly studied.Facultad de Ciencias Exacta

Mutations in the EXT1 and EXT2 genes in Spanish patients with multiple osteochondromas

Multiple osteochondromas is an autosomal dominant skeletal disorder characterized by the formation of multiple cartilage-capped tumours. Two causal genes have been identified, EXT1 and EXT2, which account for 65% and 30% of cases, respectively. We have undertaken a mutation analysis of the EXT1 and EXT2 genes in 39 unrelated Spanish patients, most of them with moderate phenotype, and looked for genotype-phenotype correlations. We found the mutant allele in 37 patients, 29 in EXT1 and 8 in EXT2. Five of the EXT1 mutations were deletions identified by MLPA. Two cases of mosaicism were documented. We detected a lower number of exostoses in patients with missense mutation versus other kinds of mutations. In conclusion, we found a mutation in EXT1 or in EXT2 in 95% of the Spanish patients. Eighteen of the mutations were novel.Fil: Sarrión, P.. Universidad de Barcelona; EspañaFil: Sangorrin, A.. Hospital Sant Joan de Déu; EspañaFil: Urreizti, R.. Universidad de Barcelona; EspañaFil: Delgado, María Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Artuch, R.. Hospital Sant Joan de Déu; EspañaFil: Martorell, L.. Hospital Sant Joan de Déu; EspañaFil: Armstrong, J.. Hospital Sant Joan de Déu; EspañaFil: Anton, J.. Hospital Sant Joan de Déu; EspañaFil: Torner, F.. Hospital Sant Joan de Déu; EspañaFil: Vilaseca, M. A.. Hospital Sant Joan de Déu; EspañaFil: Nevado, J.. Hospital Universitario La Paz; EspañaFil: Lapunzina, P.. Hospital Universitario La Paz; EspañaFil: Asteggiano, Carla Gabriela. Universidad Nacional de Córdoba; Argentina. Universidad Católica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Balcells, S.. Universidad de Barcelona; EspañaFil: Grinberg, D.. Universidad de Barcelona; Españ

Tick surveillance and zoonoses emergence in Mendoza, Argentina

La expansión de enfermedades transmi-tidas por vectores se debe a varios factores, encabe-zados por el cambio climático y global. Las garrapatas transmiten una gran variedad de patógenos a animales de compañía, al ganado y al humano. El 10% de las 867 especies de garrapatas son importantes en salud pública; 58 de estas parasitan al perro y en Argentina se han descripto 12 de ellas. En Mendoza hay reportes de Rhipicephalus sanguineus y Amblyomma tigrinum parasitando perros, estos ixódidos pueden ser vectores de diversos agentes zoonóticos como rickettsias, ehrli-chias, anaplasmas, entre otros. Existen reportes en Eu-ropa y Argentina de enfermedad en humanos causada por Rickettsia massiliae. En Buenos Aires, R. massiliae fue diagnosticada en una mujer que presentaba fiebre, erupciones pruriginosas, escara en miembro inferior y antecedentes de contacto con garrapatas de perros. En Mendoza se reportó la presencia de Rickettsia massiliae infectando Rhipicephalus sanguineus. A pesar de no ser zoonótico, ha emergido en Mendoza Hepatozoon canis, importante patógeno en perros. Ehrlichia canis, causan-te de ehrlichiosis monocitotrópica canina, es también una zoonosis. En Mendoza, entre los años 2009 a 2012, se diagnosticaron serológicamente 34 casos caninos. La importancia del perro como centinela de enfermedades zoonóticas emergentes y la vigilancia de las garrapatas que parasitan a estos hospedadores es importante para prevenir y potencialmente controlar estos patógenos. Nuestro objetivo fue comenzar con el monitoreo de ga-rrapatas presentes en perros de Mendoza

Vortices in U(1) noncommutative gauge fields

Charged vortex solutions for the noncommutative Maxwell-Higgs model in 3+1 dimensions are found. We show that the stability of these vortex solutions is lost for some, large enough, noncommutativity parameters. A nontopological charge, however, is induced by noncommutative effects.Instituto de Física La Plat

Vortices, infrared effects and Lorentz invariance violation

The Yang-Mills theory with non-commutative fields is constructed following Hamiltonian and Lagrangian methods. This modification of the standard Yang-Mills theory produces spatially localized solutions very similar to those of the standard non-Abelian gauge theories. This modification of the Yang-Mills theory contain in addition to the standard contribution, the term θμεμνρλ (Aν Fρλ + 2/3 Aν Aρ Aλ) where θμ is a given space-like constant vector with canonical dimension of energy. The Aμ field rescaling and the choice θμ=(0,0,0,θ), suggest the equivalence between the Yang-Mills-Chern-Simons theory in 2+1 dimensions and QCD in 3+1 dimensions in the heavy fermionic excitations limit. Thus, the Yang-Mills-Chern-Simons theory in 2+1 dimensions could be a codified way to QCD with only heavy quarks. The classical solutions of the modified Yang-Mills theory for the SU(2) gauge group are explicitly studied.Facultad de Ciencias Exacta