We discuss various universality aspects of numerical computations using standard algorithms. These aspects include empirical observations and rigorous results. We also make various speculations about computation in a ...
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ISBN:
(纸本)9783030015930;9783030015923
We discuss various universality aspects of numerical computations using standard algorithms. These aspects include empirical observations and rigorous results. We also make various speculations about computation in a broader sense.
Certain kinematic optimal control problems (the Clebsch problems) and their connection to classical integrable systems are considered. In particular, the rigid body problem and its rank 2k counterparts, the geodesic f...
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ISBN:
(纸本)9783030015930;9783030015923
Certain kinematic optimal control problems (the Clebsch problems) and their connection to classical integrable systems are considered. In particular, the rigid body problem and its rank 2k counterparts, the geodesic flows on Stiefel manifolds and their connection with the work of Moser, flows on symmetric matrices, and the Toda flows are studied.
We review recent results about the analysis of controlled or stochastic differential systems via local expansions in the time variable. This point of view has its origin in Lyons' theory of rough paths and has bee...
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ISBN:
(纸本)9783030015930;9783030015923
We review recent results about the analysis of controlled or stochastic differential systems via local expansions in the time variable. This point of view has its origin in Lyons' theory of rough paths and has been vastly generalised in Hairer's theory of regularity structures. Here our concern is to understand this local expansions when they feature genuinely infinite dimensional objects like distributions in the space variable. Our analysis starts reviewing the simple situation of linear controlled rough equations in finite dimensions, then we introduce unbounded operators in such linear equations by looking at linear rough transport equations. Loss of derivatives in the estimates requires the introduction of new ideas, specific to this infinite dimensional setting. Subsequently we discuss how the analysis can be extended to systems which are not intrinsically rough but for which local expansion allows to highlight other phenomena: in our case, regularisation by noise in linear transport. Finally we comment about other application of these ideas to fully-nonlinear conservations laws and other PDEs.
Poincare's center problem asks for conditions under which a planar polynomial system of ordinary differential equations has a center. It is well understood that the abel equation naturally describes the problem in...
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ISBN:
(纸本)9783030015930;9783030015923
Poincare's center problem asks for conditions under which a planar polynomial system of ordinary differential equations has a center. It is well understood that the abel equation naturally describes the problem in a convenient coordinate system. In 1990, Devlin described an algebraic approach for constructing sufficient conditions for a center using a linear recursion for the generating series of the solution to the abel equation. Subsequent work by the authors linked this recursion to feedback structures in control theory and combinatorial Hopf algebras, but only for the lowest degree case. The present work introduces what turns out to be the nontrivial multivariable generalization of this connection between the center problem, feedback control, and combinatorial Hopf algebras. Once the picture is completed, it is possible to provide generalizations of some known identities involving the abel generating series. A linear recursion for the antipode of this new Hopf algebra is also developed using coderivations. Finally, the results are used to further explore what is called the composition condition for the center problem.
The proceedings contain 25 papers. The special focus in this conference is on abelsymposium. The topics include: The Faà di Bruno Hopf Algebra for Multivariable Feedback Recursions in the Center Problem for High...
ISBN:
(纸本)9783030015923
The proceedings contain 25 papers. The special focus in this conference is on abelsymposium. The topics include: The Faà di Bruno Hopf Algebra for Multivariable Feedback Recursions in the Center Problem for Higher Order abel Equations;continuous-time autoregressive moving-average processes in hilbert space;pre- and post-lie algebras: The algebro-geometric view;Extension of the product of a post-lie algebra and application to the SISO feedback transformation group;infinite dimensional rough dynamics;Heavy tailed random matrices: How they differ from the GOE, and open problems;An analyst’s take on the BPHZ theorem;parabolic anderson model with rough dependence in space;perturbation of conservation laws and averaging on manifolds;free probability, random matrices, and representations of non-commutative rational functions;stochastic functional differential equations and sensitivity to their initial path;a review on comodule-bialgebras;renormalization: A quasi-shuffle approach;hopf algebra techniques to handle dynamical systems and numerical integrators;quantitative limit theorems for local functionals of arithmetic random waves;combinatorics on words and the theory of markoff;an algebraic approach to integration of geometric rough paths;grassmannian flows and applications to nonlinear partial differential equations;gog and magog triangles;the clebsch representation in optimal control and low rank integrable systems;the geometry of characters of hopf algebras;Shape analysis on homogeneous spaces: A generalised SRVT framework;universality in numerical computation with random data: Case Studies, Analytical Results and Some Speculations;BSDEs with default jump.
The abel Symposia volume at hand contains a collection of high-quality articles written by the world’s leading experts, and addressing all mathematicians interested in advances in deterministic and stochastic dynamic...
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ISBN:
(数字)9783030015930
ISBN:
(纸本)9783030015923
The abel Symposia volume at hand contains a collection of high-quality articles written by the world’s leading experts, and addressing all mathematicians interested in advances in deterministic and stochastic dynamical systems, numerical analysis, and control theory.
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