Double power series method for approximating cosmological perturbations [PDF]
, 2017 We introduce a double power series method for finding approximate analytical solutions for systems of differential equations commonly found in cosmological perturbation theory.
Malik, Karim A., Wren, Andrew J.
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Stratified discontinuous differential equations and sufficient conditions for robustness [PDF]
, 2015 International audienceThis paper is concerned with state-constrained discontinuous ordinary differential equations for which the corresponding vector field has a set of singularities that forms a stratification of the state domain. Existence of solutions
Hermosilla, Cristopher
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Symmetries of th-Order Approximate Stochastic Ordinary Differential Equations
Journal of Applied Mathematics, 2012 Symmetries of th-order approximate stochastic ordinary differential equations (SODEs) are studied. The determining equations of these SODEs are derived in an Itô calculus context. These determining equations are not stochastic in nature.
E. Fredericks, F. M. Mahomed
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On construction of the comparison function of program motion in probable statement
Қарағанды университетінің хабаршысы. Математика сериясы, 2019 In the class of ordinary differential equations the following modification of the inverse problem of differential systems was previously considered: to construct both a set of systems of differential equations and a set of comparison functions for the ...
G.K. Vassilina, M.I. Tleubergenov
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Classification of singular points in polarization field of CMB and eigenvectors of Stokes matrix [PDF]
, 1998 Analysis of the singularities of the polarization field of CMB, where polarization is equal to zero, is presented. It is found that the classification of the singular points differs from the usual three types known in the ordinary differential equations.
A. D. Dolgov +14 more
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Singular Perturbations of Boundary Value Problems Involving Ordinary Differential Equations [PDF]
Journal of the Society for Industrial and Applied Mathematics, 1963 In this lecture we shall consider boundary value problems Pe in which the order of the differential equation drops, or its type changes, as e → 0 so that the boundary conditions prescribed in Pe are not appropriate when e = 0, and it is not at all obvious how P0 should be defined.
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Studies of Solutions of Singularly Perturbed Ordinary Differential Equations
Bulletin of Science and Practice, 2023 The eigenvalues of the Jordan matrix determine different types of stability. It is not always possible to obtain asymptotic estimates in the real axis. Therefore, in this paper we will consider the types of stability that can be estimated in the real axis.
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Stability Analysis of New Solutions of the EYM system with Cosmological Constant [PDF]
, 1996 We analyze the stability properties of the purely magnetic, static solutions to the Einstein--Yang--Mills equations with cosmological constant. It is shown that all three classes of solutions found in a recent study are unstable under spherical ...
G. Lavrelashvili +4 more
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Geometric optics and instability for semi-classical Schrodinger equations
, 2005 We prove some instability phenomena for semi-classical (linear or) nonlinear Schrodinger equations. For some perturbations of the data, we show that for very small times, we can neglect the Laplacian, and the mechanism is the same as for the ...
A. Majda +25 more
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On expansions for nonlinear systems Error estimates and convergence issues
Comptes Rendus. Mathématique, 2023 Explicit formulas expressing the solution to non-autonomous differential equations are of great importance in many application domains such as control theory or numerical operator splitting.
Beauchard, Karine +2 more
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