Construction and analytic properties of integral manifolds of solutions of nonlinear systems of difference equations

We study properties of integral manifolds of a system of difference equations in the hyperbolic case. We prove the existence of analytic integral manifolds for a system of difference equations with analytic right sides. We examine an analytic dependence on the parameter.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 5, pp. 630–636, May, 1992.     

Control of integral manifolds loosing their attractivity in time

The work is devoted to the investigation of the integral manifolds of the nonautonomous slow-fast systems, which change their attractivity in time. The method used here is based on gluing attracting and repelling integral manifolds by using an additional control function.     

Generic integral manifolds for weight two period domains

We define the notion of a generic integral element for the Griffiths distribution on a weight two period domain, draw the analogy with the classical contact distribution, and then show how to explicitly construct an infinite-dimensional family of integral manifolds tangent to a given element.

     

Development of the Bogolyubov-Mitropol'skii method of integral manifolds

A survey is presented of some results relating to the development of the Bogolyubov-Mitropol'skii method of integral manifolds.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 1, pp. 33–46, January, 1992.     

Critical points of the integral map of the charged three-body problem

This is the first in a series of three papers where we study the integral manifolds of the charged three-body problem. The integral manifolds are the fibers of the map of integrals. Their topological type may change at critical values of the map of integrals. Due to the non-compactness of the integral manifolds one has to take into account besides ‘ordinary’ critical points also critical points at infinity. In the present paper we concentrate on ‘ordinary’ critical points and in particular elucidate their connection to central configurations. In a second paper we will study critical points at infinity. The implications for the Hill regions, i.e. the projections of the integral manifolds to configuration space, are the subject of a third paper.     

Rank gradient versus stable integral simplicial volume

We observe that stable integral simplicial volume of closed manifolds gives an upper bound for the rank gradient of the corresponding fundamental groups.     

Bounds on the fundamental groups with integral curvature bound

We extend the polynomial growth of the fundamental group, the first Betti number estimate and finiteness of fundamental groups of compact Riemannian manifolds from pointwise Ricci lower bound to integral Ricci lower bound, using a volume comparison for star-shaped domains.      

Analysis and geometry on manifolds with integral Ricci curvature bounds. II

We extend several geometrical results for manifolds with lower Ricci curvature bounds to situations where one has integral lower bounds. In particular we generalize Colding's volume convergence results and extend the Cheeger-Colding splitting theorem.

     

The Newton transformation and new integral formulae for foliated manifolds

In this article, we show that the Newton transformations of the shape operator can be applied successfully to foliated manifolds. Using these transformations, we generalize known integral formulae (due to Brito–Langevin–Rosenberg, Ranjan, Walczak, etc.) for foliations of codimension one. We obtain integral formulae involving rth mean curvature of the second fundamental form of a foliation, the Jacobi operator in the direction orthogonal to the foliation, and their products. We apply our formulae to totally umbilical foliations and foliations whose leaves have constant second order mean curvature.     

Comparative analysis of two asymptotic approaches based on integral manifolds

A comparative analysis of the two powerful asymptotic methods,ILDM and MIM (intrinsic low-dimensional manifolds; method ofinvariant manifold), is presented in the paper. The two methodsare based on the general theory of integral manifolds. The ILDMmethod is able to handle large systems of ODEs, whereas theMIM method treats systems with a limited number of unknown variables.The MIM method allows one to conduct analytical explorationof the original system and to obtain final expressions in compactform, whereas the ILDM method is a numerical approach that yieldsthe numerical form of the desired surface. The ILDM method workswell in a region where a rough splitting of the initial systemexists. Regions of the phase space where splitting does notexist are problematic for the ILDM method. In these regionsthe MIM method provides additional information regarding thedynamical behaviour of the system. A number of simple examplesare considered and analysed. It is shown that for the Semenovmodel (singularly perturbed system of ODEs) the ILDM methodgives a surface which appears close to the first order (withrespect to the corresponding small parameter) approximationof the stable (attracting) invariant manifolds. The complementaryproperties of the two asymptotic approaches suggests a feasiblecombination of the two methods, which is the subject of a futurework.     

On the asymptotics of integral manifolds of singularly perturbed systems with delay

We investigate the problem of constructing asymptotic decompositions of integral manifolds of slow variables for linear and nonlinear singularly perturbed systems with delay. Chernivtsi University, Chernivtsi. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 8, pp. 1105–1111, August, 1999.     

On a class of integrable systems with a quartic first integral

We generalize, to some extent, the results on integrable geodesic flows on two dimensional manifolds with a quartic first integral in the framework laid down by Selivanova and Hadeler. The local structure is first determined by a direct integration of the differential system which expresses the conservation of the quartic observable and is seen to involve a finite number of parameters. The global structure is studied in some detail and leads to a class of models on the manifolds {ie394-1}², ?² or ?². As special cases we recover Kovalevskaya’s integrable system and a generalization of it due to Goryachev.     

Singular integral operators on manifolds with a boundary

This paper deals with singular integral operators that are bounded, completely continuous, and Noetherian on manifolds with a boundary in weighted Hölder spaces.     

Construction of almost integral manifolds of affine control systems

We consider the problem of constructing manifolds of a special form, which are said to be almost integral, lie in the state space of an affine control system, and have the following property: the restriction of the control system to such a manifold is an almost trivial control system defining the part of trajectories of the original system lying on that manifold.     

Existence and properties of Schlicht integral manifolds

In this paper the existence and properties of integral manifolds passing through initial surfaces are investigated. A new approach via non-local assumptions, cone-valued metrics and comparison problems allows to weaken the conditions guaranteeing that the manifolds are graphs of smooth functions. By means of comparison theorems for fixed-point problems the attractivity and the existence of asymptotic phases are investigated and the estimates are improved. Supported by Alexander von Humboldt-Stiftung.     

Topological structure of integral manifolds and period-doubling bifurcation

We investigate the topological structure of integral manifolds near a closed orbit of an autonomous differential system. We prove that under some circumstances these manifolds are homeomorphic to a Möbius strip. It is shown that the appearance of a period-doubling bifurcation in systems depending on a parameter is intimately connected with the occurence of a center manifold homeomorphic to a Möbius strip. Finally we demonstate that the period-doubling bifurcation can be treated as Hopf bifurcation on a Möbius strip.

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Zusammenfassung Wir untersuchen die topologische Struktur von Integralmannigfaltigkeiten in der Nähe einer geschlossenen Lösungskurve eines autonomen Differentialgleichungssystems. Wir beweisen, daß unter gewissen Umständen diese Mannigfaltigkeiten homöomorph zu einem Möbius-Band sind. Es wird gezeigt, daß das Auftreten einer Periodenverdopplungsbifurkation in parameterabhängigen Systemen eng mit der Existenz einer Zentrumsmannigfaltigkeit verknüpft ist, die homöomorph zu einem Möbius-Band ist. Abschließend demonstrieren wir, daß die Periodenverdopplungsbifurkation als Hopf-Bifurkation auf einem Möbius-Band behandelt werden kann.

     

The method of mechanical quadratures for integral equations with fixed singularity

We investigate the method of mechanical quadratures for integral equations with fixed singularity. We establish estimates of the error of this method based on a quadrature process, which is the best in the class of differentiable functions. We prove the convergence of the method in finite-dimensional and uniform metrics. We find that the investigated quadrature method is optimal by order on the Hölder class of functions.     

Existence and bifurcation of integral manifolds with applications

In this paper a bifurcation theorem on the existence of integral manifolds is obtained by using contracting principle. As an application, sufficient conditions for a higher dimensional system to have an integral manifold are given. Especially the existence and uniqueness of a 3-dimensional invariant torus appearing in a 4-dimensional autonomous system with singularity of codimension two are proved.     

An iterative procedure for solving integral equations related to optimal stopping problems

We present an iterative algorithm for computing values of optimal stopping problems for one-dimensional diffusions on finite time intervals. The method is based on a time discretization of the initial model and a construction of discretized analogues of the associated integral equation for the value function. The proposed iterative procedure converges in a finite number of steps and delivers in each step a lower or an upper bound for the discretized value function on the whole time interval. We also give remarks on applications of the method for solving the integral equations related to several optimal stopping problems.     

Explicit construction of attracting integral manifolds for a dissipative hyperbolic equation

A dissipative sine-Gordon-type equation in a bounded domain is considered. A simple explicit construction of finite-dimensional integral manifolds with exponential tracking is proposed. Dedicated to Vladimir Aleksandrovich Kondratiev __________ Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 26, pp. 90–113, 2007.