Browsing by Author "Troncoso, R"

Now showing 1 - 7 of 7
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    Canonical sectors of five-dimensional Chern-Simons theories
    (2005) Miskovic, O; Troncoso, R; Zanelli, J
    The dynamics of five-dimensional Chem-Simons theories is analyzed. These theories are characterized by intricate self couplings which give rise to dynamical features not present in standard theories. As a consequence, Dirac's canonical formalism cannot be directly applied due to the presence of degeneracies of the symplectic form and irregularities of the constraints on some surfaces of phase space, obscuring the dynamical content of these theories. Here we identify conditions that define sectors where the canonical formalism can be applied for a class of non-Abelian Chem-Simons theories, including supergravity. A family of solutions satisfying the canonical requirements is explicitly found. The splitting between first and second class constraints is performed around these backgrounds, allowing the construction of the charge algebra, including its central extension. (c) 2005 Elsevier B.V. All rights reserved.
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    Early left atrial dysfunction is associated with suboptimal cardiovascular health
    (2020) Ocaranza Jeraldino, M. Paz; Bambs S., Claudia; Salinas Fuentealba, Manuel Alejandro; Matamala, C; García, L; Troncoso, R; Pedrozo, Z; Huidobro, A; Venegas, P; Paredes, F; Giacaman, A; Zalaquett Sepúlveda, Ricardo; Chiong, M; Verdejo Pinochet, Hugo; Ferreccio Readi, Catterina; Lavandero, S; Castro Gálvez, Pablo Federico; Gabrielli, Luigi; Ocaranza Jeraldino, M. Paz; Bambs S., Claudia; Salinas Fuentealba, Manuel Alejandro; Matamala, C; García, L; Troncoso, R; Pedrozo, Z; Huidobro, A; Venegas, P; Paredes, F; Giacaman, A; Zalaquett Sepúlveda, Ricardo; Chiong, M; Verdejo Pinochet, Hugo; Ferreccio Readi, Catterina; Lavandero, S; Castro Gálvez, Pablo Federico; Gabrielli, Luigi; Ocaranza, María Paz; Bambs S., Claudia; Salinas Fuentealba, Manuel Alejandro; Matamala, C; García, L; Troncoso, R; Pedrozo, Z; Huidobro, A; Venegas, P; Paredes, F; Giacaman, A; Zalaquett Sepúlveda, Ricardo; Chiong, M; Verdejo Pinochet, Hugo; Ferreccio Readi, Catterina; Lavandero, S; Castro Gálvez, Pablo Federico; Gabrielli, Luigi; Ocaranza, María Paz; Bambs S., Claudia; Salinas Fuentealba, Manuel Alejandro; Matamala, C; García, L; Troncoso, R; Pedrozo, Z; Huidobro, A; Venegas, P; Paredes, F; Giacaman, A; Zalaquett Sepúlveda, Ricardo; Chiong, M; Verdejo Pinochet, Hugo; Ferreccio Readi, Catterina; Lavandero, S; Castro Gálvez, Pablo Federico; Gabrielli, Luigi
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    Effects of Carvedilol upon intra- and interventricular synchrony in patients with chronic heart failure
    (EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC, 2005) Castro, PF; Mc Nab, P; Quintana, JC; Bittner, A; Greig, D; Vergara, I; Vukasovic, JL; Corbalan, R; Copaja, M; Diaz Araya, G; Chiong, M; Troncoso, R; Alcaino, H; Lavandero, S
    Radionuclide isotopic ventriculography with phase analysis was performed in 30 patients with stable heart failure (HF), determining left ventricular (LV) and interventricular contraction synchrony at baseline and after 6 months of treatment with maximal tolerated doses of carvedilol. Patients with HF had significant ventricular dyssynchrony compared with a normal population. The 50th percentile of patients with the greatest dyssynchrony at baseline showed significant improvement in ventricular synchrony after receiving carvedilol, and this was correlated positively with a reduction in end-diastolic LV volumes. (c) 2005 Elsevier Inc. All rights reserved.
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    Estimating the impact of incidents on urban controlled-access highways : an empirical analysis
    (2017) De Grange, L; Troncoso, R; Odeh Yarad, Nicolas Esteban; González, F
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    Finite action principle for Chern-Simons AdS gravity
    (2004) Mora, P; Olea, R; Troncoso, R; Zanelli, J
    A finite action principle for Chern-Simons AdS gravity is presented. The construction is carried out in detail first in five dimensions, where the bulk action is given by a particular combination of the Einstein-Hilbert action with negative cosmological constant and a Gauss-Bonnet term; and is then generalized for arbitrary odd dimensions. The boundary term needed to render the action finite is singled out demanding the action to attain an extremum for an appropriate set of boundary conditions. The boundary term is a local function of the fields at the boundary and is sufficient to render the action finite for asymptotically AdS solutions, without requiring background fields. It is shown that the Euclidean continuation of the action correctly describes black hole thermodynamics in the canonical ensemble. Additionally, background independent conserved charges associated with the asymptotic symmetries can be written as surface integrals by direct application of Noether's theorem.
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    Supersymmetric extension of the nine-dimensional continuation of the Euler density with N=2
    (2004) Hassaïne, M; Olea, R; Troncoso, R
    A local supersymmetric extension with N = 2 of the dimensional continuation of the Euler-Gauss-Bonnet density from eight to nine dimensions is constructed. The gravitational sector is invariant under local Poincare translations, and the full field content is given by the vielbein, the spin connection, a complex gravitino, and an Abelian one-form. The local symmetry group is shown to be super Poincare with N = 2 and a U(l) central extension, and the full supersymmetric Lagrangian can be written as a Chem-Simons form. (C) 2004 Published by Elsevier B.V.
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    Transgression forms and extensions of Chern-Simons gauge theories
    (2006) Mora, P; Olea, R; Troncoso, R; Zanelli, J
    A gauge invariant action principle, based on the idea of transgression forms, is proposed. The action extends the Chern-Simons form by the addition of a boundary term that makes the action gauge invariant (and not just quasi-invariant). Interpreting the spacetime manifold as cobordant to another one, the duplication of gauge fields in spacetime is avoided. The advantages of this approach are particularly noticeable for the gravitation theory described by a Chern-Simons lagrangian for the AdS group, in which case the action is regularized and finite for black hole geometries in diverse situations. Black hole thermodynamics is correctly reproduced using either a background field approach or a background-independent setting, even in cases with asymptotically nontrivial topologies. It is shown that the energy found from the thermodynamic analysis agrees with the surface integral obtained by direct application of Noether's theorem.