DGDSA - Geometria Diferencial, Sistemes Dinàmics i Aplicacions
http://hdl.handle.net/2117/3202
Fri, 26 May 2017 03:44:33 GMT2017-05-26T03:44:33ZRegularity properties of fiber derivatives associated with higher-order mechanical systems
http://hdl.handle.net/2117/104055
Regularity properties of fiber derivatives associated with higher-order mechanical systems
Colombo, Leonardo; Prieto Martínez, Pedro Daniel
The aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in T*T(k-1)Q, we find necessary and sufficient conditions for such a function to describe the dynamics of a kth-order autonomous dynamical system, thus being a kth-order Hamiltonian function. Then, we give a suitable definition of (hyper)regularity for these higher-order Hamiltonian functions in terms of their fiber derivative. In addition, we also study an alternative characterization of the dynamics in Lagrangian submanifolds in terms of the solutions of the higher-order Euler-Lagrange equations.
Thu, 04 May 2017 10:50:10 GMThttp://hdl.handle.net/2117/1040552017-05-04T10:50:10ZColombo, LeonardoPrieto Martínez, Pedro DanielThe aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in T*T(k-1)Q, we find necessary and sufficient conditions for such a function to describe the dynamics of a kth-order autonomous dynamical system, thus being a kth-order Hamiltonian function. Then, we give a suitable definition of (hyper)regularity for these higher-order Hamiltonian functions in terms of their fiber derivative. In addition, we also study an alternative characterization of the dynamics in Lagrangian submanifolds in terms of the solutions of the higher-order Euler-Lagrange equations.Equivalence between the Hamiltonian and Lagrangian formalisms for constrained systems
http://hdl.handle.net/2117/103145
Equivalence between the Hamiltonian and Lagrangian formalisms for constrained systems
Batlle Arnau, Carles; Gomis Torné, Joaquin; Pons Ràfols, Josep Maria; Román Roy, Narciso
The equivalence between the Lagrangian and Hamiltonian formalism is studied for constraint systems. A procedure to construct the Lagrangian constraints from the Hamiltonian constraints is given. Those Hamiltonian constraints that are first class with respect to the Hamiltonian constraints produce Lagrangian constraints that are FL-projectable.
Fri, 31 Mar 2017 10:40:29 GMThttp://hdl.handle.net/2117/1031452017-03-31T10:40:29ZBatlle Arnau, CarlesGomis Torné, JoaquinPons Ràfols, Josep MariaRomán Roy, NarcisoThe equivalence between the Lagrangian and Hamiltonian formalism is studied for constraint systems. A procedure to construct the Lagrangian constraints from the Hamiltonian constraints is given. Those Hamiltonian constraints that are first class with respect to the Hamiltonian constraints produce Lagrangian constraints that are FL-projectable.Structural aspects of Hamilton–Jacobi theory
http://hdl.handle.net/2117/102965
Structural aspects of Hamilton–Jacobi theory
Cariñena Marzo, José F.; Gràcia Sabaté, Francesc Xavier; Marmo, Giuseppe; Martínez Fernandez, Eduardo; Muñoz Lecanda, Miguel Carlos; Román Roy, Narciso
In our previous papers [11, 13] we showed that the Hamilton–Jacobi problem can be regarded as a way to describe a given dynamics on a phase space manifold in terms of a family of dynamics on a lower-dimensional manifold. We also showed how constants of the motion help to solve the Hamilton–Jacobi equation. Here we want to delve into this interpretation by considering the most general case: a dynamical system on a manifold that is described in terms of a family of dynamics (‘slicing vector fields’) on lower-dimensional manifolds. We identify the relevant geometric structures that lead from this decomposition of the dynamics to the classical Hamilton– Jacobi theory, by considering special cases like fibred manifolds and Hamiltonian dynamics, in the symplectic framework and the Poisson one. We also show how a set of functions on a tangent bundle can determine a second-order dynamics for which they are constants of the motion.
The final publication is available at Springer via http://dx.doi.org/10.1142/S0219887816500171
Tue, 28 Mar 2017 13:13:36 GMThttp://hdl.handle.net/2117/1029652017-03-28T13:13:36ZCariñena Marzo, José F.Gràcia Sabaté, Francesc XavierMarmo, GiuseppeMartínez Fernandez, EduardoMuñoz Lecanda, Miguel CarlosRomán Roy, NarcisoIn our previous papers [11, 13] we showed that the Hamilton–Jacobi problem can be regarded as a way to describe a given dynamics on a phase space manifold in terms of a family of dynamics on a lower-dimensional manifold. We also showed how constants of the motion help to solve the Hamilton–Jacobi equation. Here we want to delve into this interpretation by considering the most general case: a dynamical system on a manifold that is described in terms of a family of dynamics (‘slicing vector fields’) on lower-dimensional manifolds. We identify the relevant geometric structures that lead from this decomposition of the dynamics to the classical Hamilton– Jacobi theory, by considering special cases like fibred manifolds and Hamiltonian dynamics, in the symplectic framework and the Poisson one. We also show how a set of functions on a tangent bundle can determine a second-order dynamics for which they are constants of the motion.Variational principles and symmetries on fibered multisymplectic manifolds
http://hdl.handle.net/2117/101999
Variational principles and symmetries on fibered multisymplectic manifolds
Gaset Rifà, Jordi; Prieto Martínez, Pedro Daniel; Román Roy, Narciso
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 (or, what is equivalent, conservation laws), symmetries, Cartan (Noether) symmetries, gauge symmetries and different versions of Noether's theorem are studied in this ambient. In this way, this constitutes a general geometric framework for all these topics that includes, as special cases, first and higher order field theories and (non-autonomous) mechanics.
Tue, 07 Mar 2017 08:22:02 GMThttp://hdl.handle.net/2117/1019992017-03-07T08:22:02ZGaset Rifà, JordiPrieto Martínez, Pedro DanielRomán Roy, NarcisoThe 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 (or, what is equivalent, conservation laws), symmetries, Cartan (Noether) symmetries, gauge symmetries and different versions of Noether's theorem are studied in this ambient. In this way, this constitutes a general geometric framework for all these topics that includes, as special cases, first and higher order field theories and (non-autonomous) mechanics.The wave equation for stiff strings and piano tuning
http://hdl.handle.net/2117/101752
The wave equation for stiff strings and piano tuning
Gràcia Sabaté, Francesc Xavier; Sanz Perela, Tomás
We study the wave equation for a string with stiffness. We solve the equation and provide a uniqueness theorem with suitable boundary conditions. For a pinned string we compute the spectrum, which is slightly inharmonic. Therefore, the widespread scale of 12 equal divisions of the just octave is not the best choice to tune instruments like the piano. Basing on the theory of dissonance, we provide a way to tune the piano in order to improve its consonance. A good solution is obtained by tuning a note and its fifth by minimizing their beats.
Wed, 01 Mar 2017 06:51:11 GMThttp://hdl.handle.net/2117/1017522017-03-01T06:51:11ZGràcia Sabaté, Francesc XavierSanz Perela, TomásWe study the wave equation for a string with stiffness. We solve the equation and provide a uniqueness theorem with suitable boundary conditions. For a pinned string we compute the spectrum, which is slightly inharmonic. Therefore, the widespread scale of 12 equal divisions of the just octave is not the best choice to tune instruments like the piano. Basing on the theory of dissonance, we provide a way to tune the piano in order to improve its consonance. A good solution is obtained by tuning a note and its fifth by minimizing their beats.Order reduction, projectability and constrainsts of second-order field theories and higuer-order mechanics
http://hdl.handle.net/2117/100664
Order reduction, projectability and constrainsts of second-order field theories and higuer-order mechanics
Gaset Rifà, Jordi; Román Roy, Narciso
The consequences of the projectability of Poincar\'e-Cartan forms in a third-order jet bundle $J^3\pi$ to a lower-order jet bundle are analyzed using the constraint algorithm for the Euler-Lagrange equations in $J^3\pi$. The results are applied to the Hilbert Lagrangian for the Einstein equations. Furthermore, the case of higher-order mechanics is also studied as a particular situation.
Wed, 08 Feb 2017 10:31:46 GMThttp://hdl.handle.net/2117/1006642017-02-08T10:31:46ZGaset Rifà, JordiRomán Roy, NarcisoThe consequences of the projectability of Poincar\'e-Cartan forms in a third-order jet bundle $J^3\pi$ to a lower-order jet bundle are analyzed using the constraint algorithm for the Euler-Lagrange equations in $J^3\pi$. The results are applied to the Hilbert Lagrangian for the Einstein equations. Furthermore, the case of higher-order mechanics is also studied as a particular situation.A Hamiltonian study of the stability and bifurcations for the satellite problem
http://hdl.handle.net/2117/85174
A Hamiltonian study of the stability and bifurcations for the satellite problem
Muñoz Lecanda, Miguel Carlos; Rodríguez Olmos, Miguel Andrés; Teixidó Román, Miguel
We study the dynamics of a rigid body in a central gravitational field modeled as a Hamiltonian system with continuous rotational symmetries following the geometric framework of Wang et al. Novelties of our work are the use the reduced energy-momentum for the stability analysis and the treatment of axisymmetric bodies. We explicitly show the existence of new relative equilibria and study their stability and bifurcation patterns.
The final publication is available at Springer via http://dx.doi.org/10.1007/s00332-015-9257-6
Tue, 05 Apr 2016 09:34:40 GMThttp://hdl.handle.net/2117/851742016-04-05T09:34:40ZMuñoz Lecanda, Miguel CarlosRodríguez Olmos, Miguel AndrésTeixidó Román, MiguelWe study the dynamics of a rigid body in a central gravitational field modeled as a Hamiltonian system with continuous rotational symmetries following the geometric framework of Wang et al. Novelties of our work are the use the reduced energy-momentum for the stability analysis and the treatment of axisymmetric bodies. We explicitly show the existence of new relative equilibria and study their stability and bifurcation patterns.Classification and stability of relative equilibria for the two-body problem in the hyperbolic space of dimension 2
http://hdl.handle.net/2117/85167
Classification and stability of relative equilibria for the two-body problem in the hyperbolic space of dimension 2
García Naranjo Ortiz de la Huerta, Luis Constantino; Marrero, Juan Carlos; Perez Chavela, Ernesto; Rodríguez Olmos, Miguel Andrés
We classify and analyze the stability of all relative equilibria for the two-body problem in the hyperbolic space of dimension 2 and we formulate our results in terms of the intrinsic Riemannian data of the problem.
Tue, 05 Apr 2016 08:00:35 GMThttp://hdl.handle.net/2117/851672016-04-05T08:00:35ZGarcía Naranjo Ortiz de la Huerta, Luis ConstantinoMarrero, Juan CarlosPerez Chavela, ErnestoRodríguez Olmos, Miguel AndrésWe classify and analyze the stability of all relative equilibria for the two-body problem in the hyperbolic space of dimension 2 and we formulate our results in terms of the intrinsic Riemannian data of the problem.Music and mathematics. From Pythagoras to fractals
http://hdl.handle.net/2117/84848
Music and mathematics. From Pythagoras to fractals
Gràcia Sabaté, Francesc Xavier
Wed, 30 Mar 2016 10:13:59 GMThttp://hdl.handle.net/2117/848482016-03-30T10:13:59ZGràcia Sabaté, Francesc XavierMatemots
http://hdl.handle.net/2117/84706
Matemots
Gràcia Sabaté, Francesc Xavier
Fri, 18 Mar 2016 13:42:33 GMThttp://hdl.handle.net/2117/847062016-03-18T13:42:33ZGràcia Sabaté, Francesc Xavier