101,615 research outputs found

    Local matching indicators for transport problems with concave costs

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    In this paper, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of N demands and M supplies in R in the case where the cost function is concave. The computational cost of these indicators is small and independent of N. A hierarchical use of them enables to obtain an efficient algorithm

    Local matching indicators for transport with concave costs

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    In this note, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of NN demands and NN supplies in R\mathbf{R} in the case where the cost function is concave. The computational cost of these indicators is small and independent of NN. A hierarchical use of them enables to obtain an efficient algorithm

    Non-commutative calculus, optimal transport and functional inequalities in dissipative quantum systems

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    We study dynamical optimal transport metrics between density matrices associated to symmetric Dirichlet forms on finite-dimensional CC^*-algebras. Our setting covers arbitrary skew-derivations and it provides a unified framework that simultaneously generalizes recently constructed transport metrics for Markov chains, Lindblad equations, and the Fermi Ornstein--Uhlenbeck semigroup. We develop a non-nommutative differential calculus that allows us to obtain non-commutative Ricci curvature bounds, logarithmic Sobolev inequalities, transport-entropy inequalities, and spectral gap estimates

    An overview on the proof of the splitting theorem in non-smooth context

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    We give a quite detailed overview on the proof of the Cheeger-Colding-Gromoll splitting theorem in the abstract framework of spaces with Riemannian Ricci curvature bounded from below.Comment: 52 page

    The Abresch-Gromoll inequality in a non-smooth setting

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    We prove that the Abresch-Gromoll inequality holds on infinitesimally Hilbertian CD(K,N) spaces in the same form as the one available on smooth Riemannian manifolds

    Variable-range hopping in 2D quasi-1D electronic systems

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    A semi-phenomenological theory of variable-range hopping (VRH) is developed for two-dimensional (2D) quasi-one-dimensional (quasi-1D) systems such as arrays of quantum wires in the Wigner crystal regime. The theory follows the phenomenology of Efros, Mott and Shklovskii allied with microscopic arguments. We first derive the Coulomb gap in the single-particle density of states, g(ϵ)g(\epsilon), where ϵ\epsilon is the energy of the charge excitation. We then derive the main exponential dependence of the electron conductivity in the linear (L), {\it i.e.} σ(T)exp[(TL/T)γL]\sigma(T) \sim \exp[-(T_L/T)^{\gamma_L}], and current in the non-linear (NL), {\it i.e.} j(E)exp[(ENL/E)γNL]j({\mathcal E}) \sim \exp[-({\mathcal E}_{NL} / \mathcal{E})^{\gamma_{NL}}], response regimes (E{\mathcal E} is the applied electric field). Due to the strong anisotropy of the system and its peculiar dielectric properties we show that unusual, with respect to known results, Coulomb gaps open followed by unusual VRH laws, {\it i.e.} with respect to the disorder-dependence of TLT_L and ENL{\mathcal E}_{NL} and the values of γL\gamma_L and γNL\gamma_{NL}.Comment: (v2) Entirely re-written (some notations changed, new presentation and new structure). Part on the Wigner crystal taken off for short. Minor changes in results. 16 RevTex4 pages, 5 figures. (v3) Published versio
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