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Related papers: A remark for dynamic equations on time scales

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The method of monotonization of difference schemes is being considered in the paper. The method was earlier proposed by the author for stationary problems. It is investigated in the paper more profoundly. The idea of the method is to build…

Numerical Analysis · Computer Science 2014-03-13 Y. V. Troshchiev

We present spectral methods developed in our group to solve three-dimensional partial differential equations. The emphasis is put on equations arising from astrophysical problems in the framework of general relativity.

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Bonazzola , E. Gourgoulhon , J. -A. Marck

We prove a necessary condition for a dynamic integro-differential equation to be an Euler-Lagrange equation. New and interesting results for the discrete and quantum calculus are obtained as particular cases. An example of a second order…

Optimization and Control · Mathematics 2017-01-09 Monika Dryl , Delfim F. M. Torres

The effective approach to quantum dynamics allows a reformulation of the Dirac quantization procedure for constrained systems in terms of an infinite-dimensional constrained system of classical type. For semiclassical approximations, the…

General Relativity and Quantum Cosmology · Physics 2011-07-20 Martin Bojowald , Philipp A Hoehn , Artur Tsobanjan

We prove a necessary optimality condition for isoperimetric problems on time scales in the space of delta-differentiable functions with rd-continuous derivatives. The results are then applied to Sturm-Liouville eigenvalue problems on time…

Optimization and Control · Mathematics 2012-11-06 Rui A. C. Ferreira , Delfim F. M. Torres

We extend the mathematical model based on stochastic differential equations describing the error gained by an atomic clock to the cases of anomalous behavior including jumps and an increase of instability. We prove an exact iterative…

Probability · Mathematics 2015-06-04 Cristina Zucca , Patrizia Tavella

We present a theoretical framework and numerical methods for predicting the large-scale properties of solutions of partial differential equations that are too complex to be properly resolved. We assume that prior statistical information…

Numerical Analysis · Mathematics 2025-10-20 A. J. Chorin , A. Kast , R. Kupferman

In this paper we propose and solve a generalization of the Bernoulli Differential Equation, by means of a generalized fractional derivative. First we prove a generalization of Gronwall's inequality, which is useful for studying the…

General Mathematics · Mathematics 2023-08-01 Hector Carmenate , Paul Bosch , Juan E. Nápoles , José M. Sigarreta

We consider a general problem of the calculus of variations on time scales with a cost functional that is the composition of a certain scalar function with delta and nabla integrals of a vector valued field. Euler-Lagrange delta-nabla…

Optimization and Control · Mathematics 2015-09-15 Monika Dryl , Delfim F. M. Torres

Analysis of the Navier-Stokes equations in the frames of the algebraic approach to systems of partial differential equations (formal theory of differential equations) is presented.

Mathematical Physics · Physics 2022-01-05 V. V. Zharinov

We extend the phase field crystal model to accommodate exact atomic configurations and vacancies by requiring the order parameter to be non-negative. The resulting theory dictates the number of atoms and describes the motion of each of…

Computational Physics · Physics 2009-02-10 Pak Yuen Chan , Nigel Goldenfeld , Jon Dantzig

The theory of Lie remarkable equations, i.e. differential equations characterized by their Lie point symmetries, is reviewed and applied to ordinary differential equations. In particular, we consider some relevant Lie algebras of vector…

Mathematical Physics · Physics 2014-09-03 Gianni Manno , Francesco Oliveri , Giuseppe Saccomandi , Raffaele Vitolo

This is not a new result. Purpose of this work is to describe a method to search the analytical expression of the general real solution of the two-dimensional Laplace differential equation. This thing is not easy to find in scientific…

Analysis of PDEs · Mathematics 2009-10-02 Gianluca Argentini

Preparing general relativity for quantization in the Hamiltonian approach leads to the `problem of time,' rendering the world fundamentally timeless. One proposed solution is the `thermal time hypothesis,' which defines time in terms of…

History and Philosophy of Physics · Physics 2024-07-30 Eugene Y. S. Chua

Introducing certain singularities, we generalize the class of one-dimensional stochastic differential equations with so-called generalized drift. Equations with generalized drift, well-known in the literature, possess a drift that is…

Probability · Mathematics 2013-10-22 Stefan Blei , Hans-Jürgen Engelbert

This paper is devoted to derive some necessary and suficient conditions for the existence of positive solutions to a singular second order system of dynamic equations with Dirichlet boundary conditions. The results are obtained by employing…

Classical Analysis and ODEs · Mathematics 2013-02-25 Ariadna Lago , Victoria Otero-Espinar , Tania Pernas-Castaño

We present a useful method for the construction of cosmological models by solving the differential equations arising from calculating the kinematical invariants (shear, rotation, expansion and acceleration) of an observer field in proper…

General Relativity and Quantum Cosmology · Physics 2008-01-24 M. Plaue , M. Scherfner , L. A. M. de Sousa

Dynamic linear models (DLM) offer a very generic framework to analyse time series data. Many classical time series models can be formulated as DLMs, including ARMA models and standard multiple linear regression models. The models can be…

Methodology · Statistics 2019-08-20 Marko Laine

In this paper, we overview the recent progresses on the lifespan estimates of classical solutions of the initial value problems for nonlinear wave equations in one space dimension. There are mainly two directions of the developments on the…

Analysis of PDEs · Mathematics 2024-03-19 Hiroyuki Takamura

We propose a multiscale approach for predicting quantities in dynamical systems which is explicitly structured to extract information in both fine-to-coarse and coarse-to-fine directions. We envision this method being generally applicable…

Atmospheric and Oceanic Physics · Physics 2025-12-30 Karl Otness , Laure Zanna , Joan Bruna