Ara es mostren els items 100-108 de 108

    • Teoría de la relatividad general: 100 años de las ecuaciones de Einstein de la gravitación 

      Román Roy, Narciso (2015-11-25)
      Audiovisual
      Accés obert
      El 25 de novembre de 1915, Albert Einstein va presentar la forma final de les equacions de camp de la Gravitació en l'Acadèmia Prussiana de Ciències de Berlín, culminant d'aquesta manera la seva Teoria de la Relativitat ...
    • The second-order problem for k-presymplectic Lagrangian field theories: application to the Einstein–Palatini model 

      Adame Carrillo, David; Gaset Rifà, Jordi; Román Roy, Narciso (springer-Verlag, 2022-01-01)
      Article
      Accés obert
      In general, the system of 2nd-order partial differential equations made of the Euler–Lagrange equations of classical field theories are not compatible for singular Lagrangians. This is the so-called second-order problem. ...
    • Unified formalism for non-autonomous mechanical systems 

      Barbero Liñán, María; Echeverría Enríquez, Arturo; Martín de Diego, David; Muñoz Lecanda, Miguel Carlos; Román Roy, Narciso (2008-02-29)
      Article
      Accés obert
      We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of regular and non-regular time-dependent mechanical systems, which is based on the approach of Skinner and Rusk ...
    • Unified formalism for non-autonomous mechanical systems 

      Barbero Liñán, María; Echeverría Enríquez, Arturo; Martín de Diego, David; Muñoz Lecanda, Miguel Carlos; Román Roy, Narciso (AIP, 2008-06-01)
      Working paper
      Accés obert
      We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of regular and non-regular time-dependent mechanical systems, which is based on the approach of Skinner and Rusk (1983). ...
    • Unified formalism for the generalized kth-order Hamilton-Jacobi problem 

      Colombo, Leonardo; De León, Manuel; Prieto Martínez, Pedro Daniel; Román Roy, Narciso (2014-10-01)
      Article
      Accés obert
      The geometric formulation of the Hamilton-Jacobi theory enables us to generalize it to systems of higher-order ordinary differential equations. In this work we introduce the unified Lagrangian-Hamiltonian formalism for the ...
    • Unified formalism for the generalized kth-order Hamilton-Jacobi problem 

      Colombo, Leonardo; León, Manuel de; Prieto Martínez, Pedro Daniel; Román Roy, Narciso (2013-10-03)
      Report de recerca
      Accés obert
      The geometric formulation of the Hamilton-Jacobi theory enables u s to generalize it to systems of higher-order ordinary differential equations. In this w ork we introduce the unified Lagrangian-Hamiltonian formalism ...
    • Unified Lagrangian-Hamiltonian formalism for contact systems 

      De León, Manuel; Gaset Rifà, Jordi; Lainz Valcázar, Manuel; Rivas Guijarro, Xavier; Román Roy, Narciso (2020-06-23)
      Article
      Accés obert
      We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of contact autonomous mechanical systems, which is based on the approach of the pioneering work of R. Skinner and R. ...
    • Variational principles and symmetries on fibered multisymplectic manifolds 

      Gaset Rifà, Jordi; Prieto Martínez, Pedro Daniel; Román Roy, Narciso (2016-12-01)
      Article
      Accés obert
      The standard techniques of variational calculus are geometrically stated in the ambient of fiber bundles endowed with a (pre)multi-symplectic structure. Then, for the corresponding variational equations, conserved quantities ...
    • Variational principles for multisymplectic second-order classical field theories 

      Román Roy, Narciso; Prieto Martínez, Pedro Daniel (2015-09-01)
      Article
      Accés obert
      We state a unified geometrical version of the variational principles for second-order classical field theories. The standard Lagrangian and Hamiltonian variational principles and the corresponding field equations are ...