654 research outputs found

    The Liouville-type theorem for integrable Hamiltonian systems with incomplete flows

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    For integrable Hamiltonian systems with two degrees of freedom whose Hamiltonian vector fields have incomplete flows, an analogue of the Liouville theorem is established. A canonical Liouville fibration is defined by means of an "exact" 2-parameter family of flat polygons equipped with certain pairing of sides. For the integrable Hamiltonian systems given by the vector field v=(f/w,f/z)v=(-\partial f/\partial w, \partial f/\partial z) on C2{\mathbb C}^2 where f=f(z,w)f=f(z,w) is a complex polynomial in 2 variables, geometric properties of Liouville fibrations are described.Comment: 6 page

    Green Economy: Regional Priorities

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    The article is dedicated to transforming the economy of Russian regions to a green economy, which is an essential factor for the sustainable development. This is important not only for Russia but the whole world because our country has the great natural capital and provides important environmental services that support the planet biosphere. Based on the analysis of economic, social and ecological statistical data and Human Development Index (HDI) we have shown that the development of Russian Federal Districts is very unbalanced and each Russian region has its own way to new economic model. For instance, it is necessary to increase the well-being in the North Caucasus Federal District, it is important to reach higher life expectancy at birth in the Siberian and the Far Eastern Districts. It is necessary to move from the «brown» economy to a green one by using the human capital (building a knowledge economy), by applying Best Available Technologies (Techniques), by investing in efficiency of use of natural resources and by increasing energy efficiency. The transition to a green economy will help to achieve social equity and the development of human potential; it helps to move from the exploitation of non-renewable natural capital to renewable human capital. All these socio-economic measures should give decoupling effect, make risks lower, reduce the exploitation of natural capital, stop the environmental degradation and prevent the ecological crisis. Transition to the green economic model has to be accompanied by new economic development indicators, which take into account social and environmental factors.The research was supported by the grant of the Russian Foundation for Basic Research No. 14-06-00075

    Deformations of circle-valued Morse functions on surfaces

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    Let MM be a smooth connected orientable compact surface. Denote by F(M,S1)F(M,S^1) the space of all Morse functions f:MS1f:M\to S^1 having no critical points on the boundary of MM and such that for every boundary component VV of MM the restriction fV:VS1f|_{V}:V\to S^1 is either a constant map or a covering map. Endow F(M,S1)F(M,S^1) with the CC^{\infty}-topology. In this note the connected components of F(M,S1)F(M,S^1) are classified. This result extends the results of S. V. Matveev, V. V. Sharko, and the author for the case of Morse functions being locally constant on the boundary of MM.Comment: 8 pages, 4 figure

    Connected components of spaces of Morse functions with fixed critical points

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    Let MM be a smooth closed orientable surface and F=Fp,q,rF=F_{p,q,r} be the space of Morse functions on MM having exactly pp critical points of local minima, q1q\ge1 saddle critical points, and rr critical points of local maxima, moreover all the points are fixed. Let FfF_f be the connected component of a function fFf\in F in FF. By means of the winding number introduced by Reinhart (1960), a surjection π0(F)Zp+r1\pi_0(F)\to{\mathbb Z}^{p+r-1} is constructed. In particular, π0(F)=|\pi_0(F)|=\infty, and the Dehn twist about the boundary of any disk containing exactly two critical points, exactly one of which is a saddle point, does not preserve FfF_f. Let D\mathscr D be the group of orientation preserving diffeomorphisms of MM leaving fixed the critical points, D0{\mathscr D}^0 be the connected component of idM{\rm id}_M in D\mathscr D, and DfD{\mathscr D}_f\subset{\mathscr D} the set of diffeomorphisms preserving FfF_f. Let Hf{\mathscr H}_f be the subgroup of Df{\mathscr D}_f generated by D0{\mathscr D}^0 and all diffeomorphisms hDh\in{\mathscr D} which preserve some functions f1Fff_1\in F_f, and let Hfabs{\mathscr H}_f^{\rm abs} be its subgroup generated D0{\mathscr D}^0 and the Dehn twists about the components of level curves of functions f1Fff_1\in F_f. We prove that HfabsDf{\mathscr H}_f^{\rm abs}\subsetneq{\mathscr D}_f if q2q\ge2, and construct an epimorphism Df/HfabsZ2q1{\mathscr D}_f/{\mathscr H}_f^{\rm abs}\to{\mathbb Z}_2^{q-1}, by means of the winding number. A finite polyhedral complex K=Kp,q,rK=K_{p,q,r} associated to the space FF is defined. An epimorphism μ:π1(K)Df/Hf\mu:\pi_1(K)\to{\mathscr D}_f/{\mathscr H}_f and finite generating sets for the groups Df/D0{\mathscr D}_f/{\mathscr D}^0 and Df/Hf{\mathscr D}_f/{\mathscr H}_f in terms of the 2-skeleton of the complex KK are constructed.Comment: 12 pages with 2 figures, in Russian, to be published in Vestnik Moskov. Univ., a typo in theorem 1 is correcte

    Special framed Morse functions on surfaces

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    Let MM be a smooth closed orientable surface. Let FF be the space of Morse functions on MM, and F1\mathbb{F}^1 the space of framed Morse functions, both endowed with CC^\infty-topology. The space F0\mathbb{F}^0 of special framed Morse functions is defined. We prove that the inclusion mapping F0F1\mathbb{F}^0\hookrightarrow\mathbb{F}^1 is a homotopy equivalence. In the case when at least χ(M)+1\chi(M)+1 critical points of each function of FF are labeled, homotopy equivalences K~M~\mathbb{\widetilde K}\sim\widetilde{\cal M} and FF0D0×K~F\sim\mathbb{F}^0\sim{\mathscr D}^0\times\mathbb{\widetilde K} are proved, where K~\mathbb{\widetilde K} is the complex of framed Morse functions, M~F1/D0\widetilde{\cal M}\approx\mathbb{F}^1/{\mathscr D}^0 is the universal moduli space of framed Morse functions, D0{\mathscr D}^0 is the group of self-diffeomorphisms of MM homotopic to the identity.Comment: 8 pages, in Russia

    Topology of the spaces of Morse functions on surfaces

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    Let MM be a smooth closed orientable surface, and let FF be the space of Morse functions on MM such that at least χ(M)+1\chi(M)+1 critical points of each function of FF are labeled by different labels (enumerated). Endow the space FF with CC^\infty-topology. We prove the homotopy equivalence FR×M~F\sim R\times{\widetilde{\cal M}} where RR is one of the manifolds RP3{\mathbb R}P^3, S1×S1S^1\times S^1 and the point in dependence on the sign of χ(M)\chi(M), and M~{\widetilde{\cal M}} is the universal moduli space of framed Morse functions, which is a smooth stratified manifold. Morse inequalities for the Betti numbers of the space FF are obtained.Comment: 15 pages, in Russia

    ON THE CONVERGENCE OF MAPPINGS WITH k-FINITE DISTORTION.

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    We prove that a locally uniform limit of a sequence of homeomorphisms with finite k-distortion is also a mapping with finite k-distortion. We obtain also an estimation for the distortion coefficient of the limit mapping
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