A5012991466- Advanced Thermodynamics and Statistical Mechanics
- Statistical Mechanics and Entropy
- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- stochastic dynamics and bifurcation
- Quantum chaos and dynamical systems
- Spectroscopy and Quantum Chemical Studies
- Neural dynamics and brain function
- Quantum Mechanics and Non-Hermitian Physics
- Nonlinear Dynamics and Pattern Formation
- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Physics of Superconductivity and Magnetism
- Quantum optics and atomic interactions
- Quantum and electron transport phenomena
- Advanced Memory and Neural Computing
- Vaccine Coverage and Hesitancy
- Industrial Vision Systems and Defect Detection
- Advanced Optical Sensing Technologies
- COVID-19 and healthcare impacts
- Diffusion and Search Dynamics
- Neural Networks and Applications
- Advanced Chemical Physics Studies
- Advanced Mathematical Theories and Applications
- Probabilistic and Robust Engineering Design
Universidad Nacional de Hurlingham
2024
University of Buenos Aires
1992-2010
Fundación Ciencias Exactas y Naturales
1997-2007
The Abdus Salam International Centre for Theoretical Physics (ICTP)
1993-1996
Comisión de Investigaciones Científicas
1992
National Space Activities Commission
1991
Universidade Estadual de Campinas (UNICAMP)
1989
Comisión Nacional de Energía Atómica
1986-1987
Abstract Despite notable scientific and medical advances, broader political, socioeconomic behavioural factors continue to undercut the response COVID-19 pandemic 1,2 . Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel 386 academic, health, non-governmental organization, government other experts in from 112 countries territories recommend specific actions end persistent global threat public health. The developed set 41 consensus statements 57 recommendations...
We generate an observable which relates the interspike time statistics in a noise driven excitable system with its phase space global properties. Experimental results from semiconductor laser optical feedback are analyzed within this framework.
Recently it was proposed that semiconductor lasers with optical feedback present a regime where they behave as noise driven excitable units. In this work we report on an experimental study in which periodically force one of these and compare the results solutions simple model. The comparison is based topological analysis theoretical solutions.
We present a density-matrix method, based on information theory, which makes it possible to find nonzero-temperature coherent and squeezed states for the harmonic oscillator with time-dependent frequency. establish connection between appearance of relevant operators included in density matrix, compare our results previous ones that were obtained using wave functions, analyze particular case sudden jump oscillator's
On the basis of maximum-entropy principle, usual definition temperature is extended to quantal systems. Entropy, specific heats, and state equations are evaluated for bounded (i.e., spinorial systems) unbounded operators electromagnetic field systems).
An information-theoretic approach is used to give a straightforward procedure that allows one determine whether dissipative behavior can be attained for given Hamiltonian. This technique stresses the importance of an adequate set initial conditions in order obtain evolution. It shown that, although solutions may compatible with dynamical equations, they not realized just because it impossible construct would result behavior. illustrated by reference well-known Bateman generalized problem two...
We present a biologically inspired electronic neuron based on conductance model. The channels are constructed using linearly voltage controlled field effect transistors. A two channel and three circuit is developed. dynamical behavior of this system studied, showing for the either class-I or class-II excitability bursting spike frequency adaptation. Voltage-clamp-type measurements, similar to ones frequently used in neuroscience, employed order determine characteristics channels. develop an...
The dynamics and thermodynamics of a quantum time-dependent field coupled to two-level system, well known as the Jaynes-Cummings Hamiltonian, is studied, using maximum entropy principle. In framework this approach we found three different infinite sets relevant operators that describe system for any temporal dependence. These are connected by isomorphisms, which allow us consider case mixed initial conditions. A consisent set conditions established principle density operator, obtaining...
Using the maximum-entropy approach, we analyze appearance of coherent and squeezed states for Kanai-Caldirola Hamiltonian, making it possible to extend analysis easily so-called generalized harmonic oscillator a sort two-photon both zero nonzero temperature cases. A connection between possibility obtaining squeezing relevant operators included in density matrix is shown. Finally, comparison with pertinent previous results literature also presented.
Dynamical aspects of the entropy are discussed within information-theory context. General invariants motion formulated and related both to number accessible states. Examples on finite systems (Schottky anomaly, echo spins) presented. The evolution through nonequilibrium states is also discussed.
Recently, it was proposed that semiconductor lasers with optical feedback present a complex behavior can be described as noise driven excitable. In this work we investigate in which region of parameter space description is adequate. We conclude the system displays excitable subset presents low frequency fluctuations.
We study a quantum-mechanical system, prepared, at t=0, in model state, that subsequently decays into sea of other states whose energy levels form discrete spectrum with given statistical properties. An important quantity is the survival probability P(t), defined as probability, time t, to find system original state. Our main purpose analyze influence discreteness and properties on behavior P(t). Since P(t) itself quantity, we restrict our attention its ensemble average 〈P(t)〉, which...
In this paper we study a two-photon time-dependent Jaynes-Cummings model interacting with Kerr-like medium. We assumed that the electromagnetic field is in different states such as coherent, squeezed vacuum and pair atom initially excited state. studied temporal evolution of population level, second order coherence function. The results obtained show system has some similarities two-mode Stark system. analize two photon entanglement for initial conditions.
In this paper we define, in the context of dynamical algebras, a set operators that are suitable for studying any relevant quantity related to two-level Jaynes–Cummings model (JCM). We study usual JCM with and without rotating wave approximation (RWA), then add presence an external field. last case find strong driving regime there significant differences between results obtained RWA it. This holds even which requirements applying fulfilled.
Recently, De Brito and Baseia [Phys. Rev. A 40, 4097 (1989)] have studied the appearance of squeezed states for Bateman Hamiltonian. Although final results obtained in that report are correct, it is our intention to use an alternative point view, based on a density matrix defined according maximum entropy principle, which allows us reobtain those more general way.
We report the construction of an electronic device that models and replaces a neuron in midbody ganglion leech Hirudo medicinalis. In order to test behavior our device, we used well-characterized synaptic interaction between mechanosensory, sensitive pressure, (P) cell anteropagoda (because action potential shape) (AP) neuron. alternatively stimulated P connected AP neuron, studied response latter. The number timing spikes were same when parameters properly adjusted. Moreover, after changes...
A method to construct relevant Hilbert subspaces for unbounded operators is developed. The thermodynamical properties of systems described by density matrices built up out such are studied. Edge effects that arise as a consequence projections onto finite also carefully analyzed.
We show that the dissipative dynamics observed in a small quantum system coupled to large one (the bath) is consequence of increasing size bath. exemplify this effect with harmonic oscillator N oscillators. find revivals level population exist and give an estimate their period. For values N, decays exponentially coming into thermal equilibrium. conclude dissipation dynamical collective effect. Finally, we discuss extensions beyond oscillator.
We show that the uncertainty determined by minimum division of a measuring instrument can be diminished using dithering. present numerical example to introduce technique and two experiments how precision is enhanced.
Coherent and squeezed states for the time-dependent-frequency harmonic oscillator are analyzed using maximum entropy principle techniques. The information-theoretic procedure leads to results equivalent that of Wigner-function formalism, although former gives a physical interpretation involved parameters allows nonzero-temperature density matrix.