El álgebra de observables de la teoría cuántica encierra una representación del grupo simpléctico. Esta puede usarse a su vez para resolver problemas de caracterización de estados y síntesis espectral en la formulación ...

The twisted product of functions on R^2N is extended to a *-algebra of tempered distributions which contains the rapidly decreasing smooth functions, the distributions of compact support, and all polynomials, and moreover ...

We classify the gaussian Wigner functions corresponding to mixed states and show that, unlike the case of pure states, not all nonnegative mixed states are gaussian.

The dynamical evolution is described within the phase-space formalism by means of the Moyal propagator, which is the symbol of the evolution operator. Quadratic Hamiltonians on the phase space are distinguished in that ...

The phase-space approach to quantization is extended to incorporate spinning particles with Galilean symmetry. The appropriate phase space is the coadjoint orbit R^6 x S^2. From two basic principles, traciality and ...

En la Mecánica Estadística sin equilibrio, se suele derivar las ecuaciones de transporte de un sistema abierto del requisito que tal sistema forma parte de un gran sistema dinámico conservativo cerca del equilibrio. Las ...

A semigroup evolution for the 1/2-spin which admits a conservative dilation is known to be governed by a Bloch equation in a standard form. Here we construct a conservative dilation directly from the Bloch equation, thus ...

The series development of the quantum-mechanical twisted product is studied. The series is shown to make sense as a moment asymptotic expansion of the integral formula for the twisted product, either pointwise or in the ...

Si M(n) es el espacio de matrices n x n complejas, hay varias estructuras de orden en End(M(n)), el espacio de sus endomorfismos. Hay nociones de positividad, positividad fuerte y positividad completa, que son en general ...

The requirement is often made in non-equilibrium statistical mechanics that a transport equation should be derived as that which governs the subdynamics relative to a (small) part of a (large) conservative dynamical ...