3,663 research outputs found
The Second Euler-Lagrange Equation of Variational Calculus on Time Scales
The fundamental problem of the calculus of variations on time scales concerns
the minimization of a delta-integral over all trajectories satisfying given
boundary conditions. In this paper we prove the second Euler-Lagrange necessary
optimality condition for optimal trajectories of variational problems on time
scales. As an example of application of the main result, we give an alternative
and simpler proof to the Noether theorem on time scales recently obtained in
[J. Math. Anal. Appl. 342 (2008), no. 2, 1220-1226].Comment: This work was partially presented at the Workshop in Control,
Nonsmooth Analysis and Optimization, celebrating Francis Clarke's and Richard
Vinter's 60th birthday, Porto, May 4-8, 2009. Submitted 26-May-2009; Revised
12-Jan-2010; Accepted 29-March-2010 in revised form; for publication in the
European Journal of Contro
Direct and Inverse Variational Problems on Time Scales: A Survey
We deal with direct and inverse problems of the calculus of variations on
arbitrary time scales. Firstly, using the Euler-Lagrange equation and the
strengthened Legendre condition, we give a general form for a variational
functional to attain a local minimum at a given point of the vector space.
Furthermore, we provide a necessary condition for a dynamic
integro-differential equation to be an Euler-Lagrange equation (Helmholtz's
problem of the calculus of variations on time scales). New and interesting
results for the discrete and quantum settings are obtained as particular cases.
Finally, we consider very general problems of the calculus of variations given
by the composition of a certain scalar function with delta and nabla integrals
of a vector valued field.Comment: This is a preprint of a paper whose final and definite form will be
published in the Springer Volume 'Modeling, Dynamics, Optimization and
Bioeconomics II', Edited by A. A. Pinto and D. Zilberman (Eds.), Springer
Proceedings in Mathematics & Statistics. Submitted 03/Sept/2014; Accepted,
after a revision, 19/Jan/201
Discrete-Time Fractional Variational Problems
We introduce a discrete-time fractional calculus of variations on the time
scale , . First and second order necessary optimality
conditions are established. Examples illustrating the use of the new
Euler-Lagrange and Legendre type conditions are given. They show that solutions
to the considered fractional problems become the classical discrete-time
solutions when the fractional order of the discrete-derivatives are integer
values, and that they converge to the fractional continuous-time solutions when
tends to zero. Our Legendre type condition is useful to eliminate false
candidates identified via the Euler-Lagrange fractional equation.Comment: Submitted 24/Nov/2009; Revised 16/Mar/2010; Accepted 3/May/2010; for
publication in Signal Processing
The Variational Calculus on Time Scales
The discrete, the quantum, and the continuous calculus of variations, have
been recently unified and extended by using the theory of time scales. Such
unification and extension is, however, not unique, and two approaches are
followed in the literature: one dealing with minimization of delta integrals;
the other dealing with minimization of nabla integrals. Here we review a more
general approach to the calculus of variations on time scales that allows to
obtain both delta and nabla results as particular cases.Comment: 15 pages; Published in: Int. J. Simul. Multidisci. Des. Optim. 4
(2010), 11--2
Noether's symmetry theorem for nabla problems of the calculus of variations
We prove a Noether-type symmetry theorem and a DuBois-Reymond necessary
optimality condition for nabla problems of the calculus of variations on time
scales.Comment: Submitted 20/Oct/2009; Revised 27/Jan/2010; Accepted 28/July/2010;
for publication in Applied Mathematics Letter
Variational Optimal-Control Problems with Delayed Arguments on Time Scales
This article deals with variational optimal-control problems on time scales
in the presence of delay in the state variables. The problem is considered on a
time scale unifying the discrete, the continuous and the quantum cases. Two
examples in the discrete and quantum cases are analyzed to illustrate our
results.Comment: To apear in Advances in Difference Equation
Fractional variational calculus for nondifferentiable functions
We prove necessary optimality conditions, in the class of continuous
functions, for variational problems defined with Jumarie's modified
Riemann-Liouville derivative. The fractional basic problem of the calculus of
variations with free boundary conditions is considered, as well as problems
with isoperimetric and holonomic constraints.Comment: Submitted 13-Aug-2010; revised 24-Nov-2010; accepted 28-March-2011;
for publication in Computers and Mathematics with Application
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