No labeling quantum mechanics of indiscernible particles

Our aim in this paper is to show an example of the formalism we have developed to avoid the label-tensor-product-vector-space-formalism of quantum mechanics when dealing with indistinguishable quanta. States in this new vector space, that we call the Q-space, refer only to occupation numbers and permutation operators act as the identity operator on them, reflecting in the formalism the unobservability of permutations, a goal of quasi-set theory.Instituto de Física La Plat

No labeling quantum mechanics of indiscernible particles

Our aim in this paper is to show an example of the formalism we have developed to avoid the label-tensor-product-vector-space-formalism of quantum mechanics when dealing with indistinguishable quanta. States in this new vector space, that we call the Q-space, refer only to occupation numbers and permutation operators act as the identity operator on them, reflecting in the formalism the unobservability of permutations, a goal of quasi-set theory.Comment: submitted to the special issue of the International Journal of Theoretical Physics dedicated to the IQSA Meeting "Quantum Structures Brussels-Gdansk '08

Location preferences of fission products in high density U(Mo) dispersion fuel element

In the frame of the RERTR (Reduced Enrichment for Research and Test Reactors) program a fuel element is being developed with the concept of high density bcc uranium that can remain stable during fabrication and later irradiation, dispersed in aluminum powder. The whole constitutes a compact material which is later rolled with an aluminum-silicon clad plate. Under further irradiation, an interaction layer (IL) grows through a diffusion process around the fuel element particle, leading to the swelling of the fuel element and formation of pores. This behavior can lead to catastrophic failure of the disperse fuel. Therefore it is our great interest to gain knowledge about the influence the fission products (FP) have over the IL formation and swelling. The stable compounds that have been observed in the IL of U(Mo)/Al(Si) tested in diffusion pair experiments are U(Al, Si)3, USi2, U1+xSi2-x, U3Si5 UMo2Al20 and U6Mo4Al43. Among them, U(Al, Si)3 has been observed to remain stable when subject to irradiation, delaying or stopping the IL swelling. Compositional analysis shows that La, Ce, Pr and Nd are some of the FP present in the burned dispersed fuel. Hence, these are the considered elements for a first evaluation of the problem that we performed in this work by means of computational methods.Fil: Alonso, Paula Regina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Forti, Mariano D.. Universidad Nacional de San Martín; ArgentinaFil: Kniznik, Laura. Universidad Nacional de San Martín; ArgentinaFil: Rubiolo, Gerardo Hector. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torres, Dario Nelson. No especifíca;Fil: Gargano, Pablo Hugo. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

One-loop Vilkovisky-DeWitt Counterterms for 2D Gravity plus Scalar Field Theory

The divergent part of the one-loop off-shell effective action is computed for a single scalar field coupled to the Ricci curvature of 2D gravity ($c \phi R$), and self interacting by an arbitrary potential term $V(\phi)$. The Vilkovisky-DeWitt effective action is used to compute gauge-fixing independent results. In our background field/covariant gauge we find that the Liouville theory is finite on shell. Off-shell, we find a large class of renormalizable potentials which include the Liouville potential. We also find that for backgrounds satisfying $R=0$, the Liouville theory is finite off shell, as well.Comment: 19 pages, OKHEP 92-00