The Dyer-Roeder relation in a universe with particle production [PDF]
We have obtained analytical exact solutions of the Dyer-Roeder equation in a cosmological model where creation of particles occurs at the expenses of the gravitational field. We discussed the influences of inhomogeneities in the path of a light beam on the apparent diameter of astrophysical objects and consider both redshift independent as redshift ...
arxiv +1 more source
Política lingüística familiar. O papel dos proxenitores pro-galego na transmisión interxeracional
Nunha sociedade bilingüe cada individuo adulto ten as súas propias prácticas lingüísticas e crenzas sobre a elección do idioma dentro da familia; polo tanto, as prácticas lingüísticas no ámbito familiar son sumamente importantes para entender o
Anik Nandi
semanticscholar +1 more source
Extended open inflationary universes [PDF]
In this paper we study a type of one-field model for open inflationary universe models in the context of the Jordan-Brans-Dicke theory. In the scenario of a one-bubble universe model we determine and characterize the existence of the Coleman-De Lucia instanton, together with the period of inflation after tunnelling has occurred.
arxiv +1 more source
Functionally Graded Media [PDF]
The notions of uniformity and homogeneity of elastic materials are reviewed in terms of Lie groupoids and frame bundles. This framework is also extended to consider the case Functionally Graded Media, which allows us to obtain some homogeneity conditions.
arxiv +1 more source
Adiabatic decaying vacuum model for the universe [PDF]
We study a model that the entropy per particle in the universe is constant. The sources for the entropy are the particle creation and a lambda decaying term. We find exact solutions for the Einstein field equations and show the compatibilty of the model with respect to the age and the acceleration of the universe.
arxiv +1 more source
Noncommutative solitons and instantons [PDF]
I review in this talk different approaches to the construction of vortex and instanton solutions in noncommutative field theories.
arxiv +1 more source
A nonlocal discretization of fields [PDF]
A nonlocal method to obtain discrete classical fields is presented. This technique relies on well-behaved matrix representations of the derivatives constructed on a non--equispaced lattice. The drawbacks of lattice theory like the fermion doubling or the breaking of chiral symmetry for the massless case, are absent in this method.
arxiv +1 more source
Estudio Teórico del espectro de emisión para un sistema microcavidad-punto cuántico en una aproximación de campo medio (Theoretical study of emission spectrum for a quantum dot-microcavity system in a mean field approximation) [PDF]
En este trabajo, se obtiene una expresi\'on num\'erica para calcular el espectro de emisi\'on de un sistema microcavidad-punto cu\'antico usando una teor\'ia de campo medio en el formalismo de la matriz densidad. El sistema modelado es un micropilar semiconductor que contiene un \'unico punto cu\'antico en el interior de la microcavidad, este sistema ...
arxiv +1 more source
Ángel Cerrato Álvarez: o compromiso e a galeguidade dun etnógrafo senlleiro
Nesta contribución estúdase a traxectoria e a obra dun etnógrafo e historiador, Ángel Cerrato Álvarez, de nacenza vallisoletana e de galeguidade entregada e comprometida.
Alexandre Rodríguez Guerra
semanticscholar +1 more source
Resultados das terminacións -ANUM, -ANAM, -ANOS e -ANAS en galego
O obxectivo desta investigación consiste en describi-los resultados das terminacións -anum, -anam, ‑anos e -anas no concello de Castrelo do Val, na comarca verinesa, no conxunto do galego e no continuum dialectal galego-portugués.
A. S. Alonso Núñez
semanticscholar +1 more source