Universidad de Santiago de Chile
Facultad de Ciencias
A model is presented for the characterization of dissipative effects on highly nonlinear waves in one-dimensional dry granular media. The model includes three terms: Hertzian, viscoelastic, and a term proportional to the square of the... more
derivation of the effective lagrangian for non-relativistic quantum chromodynamics and the heavy quarks effective field theory is given. Our calculation provides of a simple and systematic method of calculation of the full off shell... more
The axial anomaly and fermion condensate in the light cone Schwinger model are studied, following path integral methods. This formalism allows for a simple and direct calculation of these and other vacuum dependent phenomena.
We study the decoherence process of a harmonic oscillator in a dissipative environment by considering the von Neumann entropy. Derivatives of the von Neumann entropy around the initial time exhibit divergences when the system is initially... more
We show that it is possible, in opposition to a previous conjecture, to derive a Nielsen identity for the effective action in the case of the generalized $R_\xi $-gauge, where the gauge function explicitly depends on the gauge parameter... more
We show that convexity of the effective action follows from its functional flow equation. Our analysis is based on a new, spectral representation. The results are relevant for the study of physical instabilities. We also derive... more
We study exact renormalisation group equations for the 3d Ising universality class. At the Wilson-Fisher fixed point, symmetric and antisymmetric correction-to-scaling exponents are computed with high accuracy for an optimised cutoff to... more
We show that convexity of the effective action follows from its functional flow equation. Our analysis is based on a new, spectral representation. The results are relevant for the study of physical instabilities. We also derive... more
We study exact renormalisation group equations for the 3d Ising universality class. At the Wilson-Fisher fixed point, symmetric and antisymmetric correction-to-scaling exponents are computed with high accuracy for an optimised cutoff to... more
It is shown that the phenomenon of self-similarity appears in granular media, with an intergrain potential $V \propto \delta^{p+1}$, $p > 1$, where $\delta$ is the overlap between the grains. Although this fact can be traced back in... more
Recibido el 18 de enero de 2001; aceptado el 8 de junio del 2001
We present a novel way to compute the one-loop ring-improved effective potential numerically, which avoids the spurious appearence of complex expressions and at the same time is free from the renormalization ambiguities of the... more
The flow equations or exact RG equations for the Higgs Top System are solved to leading order in 1/N c . This allows to relate arbitrary bare actions with this field content continuously to effective low energy theories, and we find the... more
Generalized universality, as recently proposed, postulates a universal non-Gaussian form of the probability density function (PDF) of certain global observables for a wide class of highly correlated systems of finite volume N . Studying... more
In granular media, the characterization of the behavior of solitary waves around interfaces is of importance in order to look for more applications of these systems. We study the behavior of solitary waves at both interfaces of a... more
A detailed numerical study of the scattering of solitary waves by a barrier, in a granular media with Hertzian contact, shows the existence of secondary multipulse structures generated at the interface of two "sonic vacua", which have a... more