Time filter

Source Type

San Carlos de Bariloche, Argentina

The Bariloche Atomic Centre is one of the research and development centres of the Argentine National Atomic Energy Commission. As it name implies, it is located in the city of San Carlos de Bariloche. Bariloche Atomic Centre is responsible for research in physics and nuclear engineering. It also hosts the Balseiro Institute, a collaboration between National University of Cuyo and the National Atomic Energy Commission. The Bariloche Atomic Centre opened in 1955 with its first director, José Antonio Balseiro. Wikipedia.

Aligia A.A.,Bariloche Atomic Center
Journal of Physics Condensed Matter | Year: 2012

Using nonequilibrium renormalized perturbation theory, we calculate the retarded and lesser self-energies, the spectral density () near the Fermi energy, and the conductance G through a quantum dot as a function of a small bias voltage V, in the general case of electronhole asymmetry and intermediate valence. The linear terms in and V are given exactly in terms of thermodynamic quantities. When the energies necessary to add the first electron (E d) and the second one (E d+U) to the quantum dot are not symmetrically placed around the Fermi level, G has a term linear in V if, in addition, either the voltage drop or the coupling to the leads is not symmetric. The effects of temperature are discussed. The results simplify for a symmetric voltage drop, a situation usual in experiment. © 2012 IOP Publishing Ltd. Source

Jagla E.A.,Bariloche Atomic Center
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

The Olami-Feder-Christensen model describes a limiting case of an elastic surface that slides on top of a substrate and is one of the simplest models that display some features observed in actual seismicity patterns. However, temporal and spatial correlations of real earthquakes are not correctly described by this model in its original form. I propose and study a modified version of the model, which includes a mechanism of structural relaxation. With this modification, realistic features of seismicity emerge, which are not obtained with the original version, mainly: aftershocks that cluster spatially around the slip surface of the main shock and follow the Omori law, and averaged frictional properties similar to those observed in rock friction, in particular the velocity-weakening effect. In addition, a Gutenberg-Richter law for the decaying of number of earthquakes with magnitude is obtained, with a decaying exponent within the range of experimentally observed values. Contrary to the original version of the model, a realistic value of the exponent appears without the necessity to fine tune any parameter. © 2010 The American Physical Society. Source

Jagla E.A.,Bariloche Atomic Center
Physical Review Letters | Year: 2013

The Drössel-Schwabl model of forest fires can be interpreted in a coarse-grained sense as a model for the stress distribution in a single planar fault. Fires in the model are then translated to earthquakes. I show that when a second class of trees that propagate fire only after some finite time is introduced in the model, secondary fires (analogous to aftershocks) are generated, and the statistics of events becomes quantitatively compatible with the Gutenberg-Richter law for earthquakes, with a realistic value of the b exponent. The change in exponent is analytically demonstrated in a simplified percolation scenario. Experimental consequences of the proposed mechanism are indicated. © 2013 American Physical Society. Source

Fiorini F.,Bariloche Atomic Center
Physical Review Letters | Year: 2013

Born-Infeld determinantal gravity formulated in Weitzenböck spacetime is discussed in the context of Friedmann-Robertson-Walker (FRW) cosmologies. It is shown how the standard model big bang singularity is absent in certain spatially flat FRW spacetimes, where the high energy regime is characterized by a de Sitter inflationary stage of geometrical character, i.e., without the presence of the inflaton field. This taming of the initial singularity is also achieved for some spatially curved FRW manifolds where the singularity is replaced by a de Sitter stage or a big bounce of the scale factor depending on certain combinations of free parameters appearing in the action. Unlike other Born-Infeld-like theories in vogue, the one here presented is also capable of deforming vacuum general relativistic solutions. © 2013 American Physical Society. Source

Huerta M.,Bariloche Atomic Center
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

We calculate numerically the logarithmic contribution to the entanglement entropy of a cylindrical region in three spatial dimensions for both, free scalar and Dirac fields. The coefficient is universal and proportional to the type c conformal anomaly in agreement with recent analytical predictions. We also calculate the mass corrections to the entanglement entropy for scalar and Dirac fields in a disk. These apparently unrelated problems make contact through the dimensional reduction procedure valid for free fields whereby the entanglement entropy for the cylinder can be calculated as an integral over masses of the disk entanglement entropies. Coming from the same numerical evaluation in the lattice, each coefficient is cross checked by the other, testing in this way the two results simultaneously. © 2012 Elsevier B.V. Source

Discover hidden collaborations