325,854 research outputs found
Genetic Heritage Evolution by Stochastic Transmission in the optimal design of water distribution networks
No full textAndrea Bolognesi, Cristiana Bragalli, Angela Marchin and Sandro Artinahttp://www.elsevier.com/wps/find/journaldescription.cws_home/422911/description#descriptio
Multiobjective design of water distribution networks through the generation of pseudofronts in the hydraulically feasible region
No full textAbstract not availableAndrea Bolognesi, Cristiana Bragalli, Angela Marchi, and Sandro Artin
Born Reciprocity and Cosmic Accelerations
No full textThe trans-Planckian theory is a model that realizes concretely the Born
reciprocity idea, which is the postulate of absolute equivalence between
coordinate and momenta . This model is intrinsically global, and thus it
is naturally implemented in a cosmological setting. Cosmology and Born
reciprocity are made for each other. Inflation provides the essential mechanism
to suppress the terms coming from the dual part of the action. The
trans-Planckian theory provides an explanation for the present acceleration of
the universe scale factor. This is possible just considering a simple model
that contains gravity, one gauge field plus one matter field (to be identified
with dark matter), together with the reciprocity principle
Skyrmions in orientifold and adjoint QCD
No full textThis contribution is a review of recent developments regarding the Skyrmion sector of higher representation QCD. This review is mostly based on the results of [1, 2, 3]. Ordinary QCD is a SU(n) gauge theory with nf Dirac quarks in the fundamental representation. Changing the representation of quarks leads to different and interesting theories, which are not as well studied as ordinary QCD. In order to be able to have a consistent asymptotically free large n limit, we must limit ourselves to three cases: two-index representation (symmetric or anti-symmetric) and adjoint representation. We call the first two "orientifold QCD (S/A)" and the last one "adjoint QCD". Skyrmions of the low-energy effective Lagrangian shall be the main subject of this review. There are puzzling aspects, both in orientifold and adjoint QCD, regarding the identification of the Skyrmion and its quantum stability, that have not yet been understood. We shall explain these problems and the solution we proposed for them. The first part is dedicated to the two-index (S/A) representation. Here the challenge is to identify the correct particle in the spectrum that has to be identified with the Skyrmion. It turns out not to be the simplest baryon (as in ordinary QCD) but a baryonic state with higher charge, precisely composed of n(n±1)/2 quarks. Although not the simplest among the baryons, it is the one that minimizes the mass per unit of baryonic charge and thus is the most stable among them. The second part is devoted to the quarks in the adjoint representation. The task here assumes a different perspective. We still have a Skyrmion, but we do not have a baryon charge, like in ordinary QCD. An important role is now played by a massive fermion that must be considered in the low-energy effective Lagrangian. Through this fermion, the Skyrmion acquires an anomalous fermionic number (-1)F and, as a consequence, an odd relationship between the latter and its spin/statistic. This implies a Z2 stability of the Skyrmion
The holomorphic tension of non-Abelian vortices
No full textWe continue the work hep-th/0411075 considering here the case of degenerate masses. A non-Abelian vortex arises in r-vacua upon the breaking by a superpotential for the adjoint field. We find the BPS tension in the strong coupling regime computing the dual-quark condensate. Then we find that it is equal to a simple quantity in the chiral ring of the theory and so we conjecture the validity of our result out of the strong coupling regime. Our result gives an interesting hint about the duality r ↔ Nf - r, seeing it as the exchange first ↔ second sheet of N = 1 Riemann surface. © 2005 Elsevier B.V. All rights reserved
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