Tao Wang (Fudan University Shanghai)
Abstract: In this talk, we introduce Cheeger type constants via isocapacitary constants introduced by Maz'ya to estimate first Dirichlet, Neumann and Steklov eigenvalues on a finite subgraph of a...
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Florentin Münch (Universität Leipzig)
Abstract: In this talk, we prove that every salami has exactly two ends. As is well known to experts, a salami is a weighted graph with non-negative Ollivier Ricci curvature with at least two ends of...
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Alexandro Luna (UCI)
Abstract: We prove that the Hausdorff dimension of the spectrum of a Sturmian Hamiltonian of bounded type tends to one as the coupling constant tends to zero. We give a sketch of the proof which...
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Haonan Zhang (University of South Carolina)
Abstract: Recently, Eldan and Gross developed a stochastic analysis approach to proving functional inequalities on discrete hypercubes. Motivated by a conjecture of Talagrand, one of their main...
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Christopher Cedzich (Düsseldorf)
Abstract: In this talk, we introduce the unitary almost-Mathieu operator (UAMO) and discuss its connections to several model systems in physics and mathematics. We draw parallels to the self-adjoint...
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David Fajman (Universität Wien)
Abstract:
Fluids are generally known to form shocks in finite time from small inhomogeneities. When the fluid evolves in an expanding spacetime, as in standard cosmology,
the expansion of spacetime...
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Sven Gnutzmann
Abstract: Given an arbitrary Hermitian matrix, considered as a finite discrete quantum Hamiltonian, we use methods from graph and ergodic theories to construct a corresponding unitary scattering...
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Matthias Täufer (Hagen)
Abstract: We speak about the heat content at time t on metric graphs. This quantity measures how much mass of a constant initial configuration remains in the graph at time t under the action of the...
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Gilad Sofer (Technion)
Abstract: A classical result by Belissard et al states that the spectrum of a 1-dimensional Hamiltonian with a Sturmian potential is a singular continuous Cantor set of Lebesgue measure zero. More...
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Pavel Exner (Prague)
Abstract: The topic of this talk are quantum graphs with the vertex coupling which does not preserve the time-reversal invariance. As a case study the simplest example with the asymmetry being maximal...
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Jonathan Taylor (UP)
Abstract: Given a directed row-finite graph, one may define representations of such a graph in C*-algebras and deduce the existence of a unique C*-algebra that is universal for such representations....
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Anna Muranova (University of Warmia and Mazury in Olsztyn)
Abstract: In this talk we consider graphs, whose weights belong to an ordered field. It is known, that in the case of real weights every weighted graph defines a Markov chain, whose states are...
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Konstantin Pankrashkin (Carl von Ossietzky Universität Oldenburg)
Abstract: For a class of weighted infinite metric trees we propose a definition of the boundary trace which maps H^1-functions on the tree to L^2-functions on a compact Riemannian manifold. For a...
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Prof. Olaf Post (Trier)
Abstract: In this talk I will present a construction of discrete magnetic non-isomorphic graphs with isospectral Laplacians. The construction is based on gluing building blocks according to a...
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Simon Barthelmé
Abstract: Joint work with Nicolas Tremblay, Pierre-Olivier Amblard
Determinantal Point Processes (DPPs) are an important class of models of random sets that arise in many areas of mathematics and...
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Renaud Leplaideur (Université de la Nouvelle-Calédonie)
Abstract: I will present a new object, called substreetution, which is an extension of substitutions in dynamics (Z-action) to colored trees (free-group action). The main part of the talk will be...
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Paul Hege (Tübingen)
Abstract: The spectrum of infinite-volume operators is often computed numerically by considering finite sections with Dirichlet or periodic boundary conditions, but such artificial boundary conditions...
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Dr. Christian Seifert (TUHH)
Abstract: Given a radial metric tree graph, we consider Laplacians with self-adjoint coupling conditions at the vertices. We consider the questions whether presence of absolutely continuous spectrum...
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Ofir David (Technion)
Abstract: In 1978, Apery proved the irrationality of the Riemann zeta value ζ(3) by utilizing a fast converging sequence of rational approximations. However, the details of his proof remained...
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Selim Sukhtaiev (Auburn University)
Abstract: This talk is centered around a symplectic approach to eigenvalue problems for systems of ordinary differential operators (e.g., Sturm-Liouville operators, canonical systems, and quantum...
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Johannes Happich (Leipzig)
Abstract: When comparing the complexity of different aperiodic quasicrystals, it appears that linear repetitivity is a useful property that only applies to the - in some sense - most regular...
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Gregory Berkolaiko
Abstract:
Eigenvalue interlacing is a tremendously useful tool in linear algebra
and spectral analysis. In its simplest form, the interlacing
inequality states that a rank-one positive perturbation...
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James Kennedy
Abstract: SMPs offer a way of dividing a given object (domain, manifold or graph) into a given number of pieces in an ``analytically optimal'' way: typically, one attempts to minimise an energy...
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Dr. Christian Rose (Potsdam)
Abstract: On Riemannian manifolds the conjunction of Gaussian upper heat kernel bounds and the volume doubling property of balls are equivalent to Sobolev inequalities in arbitrarily small balls. The...
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Marvin Weidner (Barcelona)
Abstract: The celebrated De Giorgi-Nash-Moser theory establishes Hölder regularity of solutions to second order equations in divergence form without any regularity assumptions on the coefficients....
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Gilad Sofer (Technion)
Abstract: Sturmian Hamiltonians appear in mathematical physics as popular models for one-dimensional quasicrystals. This family of discrete quasiperiodic Schrödinger operators, including the well...
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Florian Fischer (Potsdam)
Abstract: We show various sharp Hardy-type inequalities for the linear and quasi-linear Laplacian on non-compact harmonic manifolds with a particular focus on the case of Damek-Ricci spaces. Our...
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Matti Richter (Potsdam)
Abstract: We study positive generalized eigenfunctions of Schrödinger operators associated to graphs with cocompact group actions of nilpotent groups. For such a graph, we investigate the topological...
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Prof. Dr. Peter Stollmann (Chemnitz)
Abstract: We report on recent results from a joint work with B. Güneysu, S. Pigola and. G. Veronelli. Using a new notion of subharmonicity we can prove a version of the Braverman-Milatovic-Shubin...
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Dr. Ulrik Enstad (Stockholm University)
Abstract: Many structured function systems in harmonic analysis arise from the action of a unitary group representation on a single vector in the underlying Hilbert space. A central question is...
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Shubham Gupta
Abstract: In the continuum, symmetrization inequalities are a fundamental tool in various parts of analysis: variational problems, spectral geometry, mathematical physics just to name a few. In this...
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Prof. Yehuda Pinchover (Technion)
Abstract: Let p ∈ (1,∞) and Ω⊂ℝN be a domain.
Let A:=(aij) ∈ L∞loc(Ω ; ℝN× N) be a symmetric and locally uniformly positive definite matrix. Set |ξ|A2:= ∑i,j=1N aij(x) ξi ξj, ξ ∈ ℝN, and let V be...
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Prof. Ron Rosenthal (Technion)
Abstract: In the talk we will introduce a model for random simplicial complexes which are high-dimensional counterparts of random regular graphs.
We will present some results for such random complexes...
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Bernard Helffer (Nantes Université)
in collaboration with
G. Berkolaiko, G. Cox, and M. Persson Sundqvist
Abstract
Recent work of the authors and their collaborators has uncovered fundamental connections between the...
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Anna Muranova (University of Warmia)
Abstract:
We consider discrete normalized Laplacian for finite graphs, whose edge-weights belong to an arbitrary real-closed ordered field. We show that eigenvalues of Laplacian always belong to the...
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Borbola Gerhat (Prague)
Abstract
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Tanja Eisner (Leipzig)
Abstract: We discuss a proof of multiple recurrence for ergodic systems (and thereby of Szemerédi's theorem) being a mixture of three known proofs. It is based on a conditional version of the...
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Christian Seifert (Technische Universität Hamburg)
Abstract: Given an abstract Cauchy problem in a Banach space we consider two questions:
1. Can we steer the system to any given state (or to zero, say) in finite time by some inhomogeneity?
2. Can we...
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Xueping Huang (Nanjing University)
Abstract: We consider the discrete analogue of semi-linear differential inequalities on weighted graphs. Under some technical conditions, we obtain almost sharp volume growth criteria for the...
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Christoph Richard (Erlangen)
Abstract: We define a notion of uniform density on translation bounded measures in unimodular amenable locally compact Hausdorff groups, which is based on a group invariant introduced by Leptin in...
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Anton Gorodetski (UCI)
Abstract: In this talk we will formulate a non-stationary version of the Furstenberg Theorem on random matrix products. As a main application we will discuss how it can be used to prove a...
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Noema Nicolussi (Potsdam)
There are many interesting parallels between analysis on Riemann surfaces and graphs. Both settings admit a Laplace operator and the Poisson equation reflects crucial geometric information.
Motivated...
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Prof. Daniel Lenz (Universität Jena)
Abstract: Uniformity of continuous SL(2,R) valued cocycles over uniquely dynamical systems has featured in various contexts. Walters asked in '86 whether every uniquely ergodic system admits a...
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Ali Ben Amor (Gabès, Tunisia)
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Shiwen Zhang (University of Minnesota)
Abstract: The localization landscape theory, introduced in 2012 by Filoche and Mayboroda, considers the landscape function u solving Hu=1 for an operator H. The landscape theory has remarkable power...
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Tatiana Smirnova-Nagnibeda (Genf)
Abstract: In this talk we will discuss some results in the spectral theory of infinite graphs obtained using techniques coming from the study of self-similar groups and their actions.
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Bobo Hua (Fudan University Shanghai)
Abstract: We prove sharp l^2 decay estimates of nonnegative generalized subharmonic functions on graphs with positive Laplacian spectrum, which generalizes the result by Li and Wang on Riemannian...
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Florentin Münch
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Florentin Münch (MPI Leipzig)
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Christian Rose (Universität Bremen)
Abstract: The heat kernel as the minimal fundamental solution of the heat equation is one of the most important objects studied in geometric analysis and encodes the geometry of the underlying space...
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Daniel Lenz (Jena)
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Philipp Hake (Leipzig)
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Elias Zimmermann (Leipzig)
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Safoura Zadeh (MFO Leibniz Fellow)
Please contact Siegfried Beckus (beckus@uni-potsdam.de) if you are interested to join the talk.
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Tanja Eisner (Leipzig)
Title: Wiener's lemma along subsequences.
Abstract: We discuss the validity of the classical Wiener lemma and the extremal behaviour of a measure on the unit circle via the behavior of its Fourier...
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Alexey Klimenko
Please contact Siegfried Beckus (beckus@uni-potsdam.de) if you are interested to join the talk.
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Jean Bellissard (University of Münster)
Please contact Siegfried Beckus (beckus@uni-potsdam.de) if you are interested to join the talk.
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Alexander Grigor'yan (University of Bielefeld)
Please contact Siegfried Beckus (beckus@uni-potsdam.de) if you are interested to join the talk.
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Matti Richter
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Dr. Siegfried Beckus (Universität Potsdam)
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Uzy Smilansky (Weizmann Institute of Science)
Trace formulae are one of the most important tools in a large number of fields ranging from quantum chaos via spectral geometry, graphs and number theory. Here, I shall present two rather...
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Dr. Christian Rose (MPI Leipzig)
The Kato condition on the negative part of the Ricci curvature turned out to be an appropriate generalization of Lp- curvature conditions that can be used to investigate geometric and topological...
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Anna Muranova (Bielefeld University)
Abstract
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Bernard Helffer (University of Paris-Sud)
Abstract: We revisit Courant's nodal domain property for linear combinations of eigenfunctions. This property was proven by Sturm (1836) in the case of dimension 1. Although stated as true for the...
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Max Kämper (TU Dortmund)
Random Schrödinger operators are a model for metals with random impurities and this talk will present them for the special case of the Anderson operator on a lattice. We will introduce the integrated...
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Noema Nicolussi (University of Vienna)
Abstract
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Prof. Dr. Ram Band (Israel Institute of Technology - Technion)
We discuss the number of zeros of Laplacian eigenfunctions on a metric (quantum) graph.
The n-th eigenfunction has at least n-1 zeros and at most n-1+\beta zeros, where \beta is the number of graph...
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Philipp Bartmann
We will discuss aspects of classical interpolation theory including properties of the Hardy–Littlewood maximal function and Marcinkiewicz’s interpolation theorem. Further, we will establish the...
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Jonas Grünberg
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Christian Scholz
Consider a countable set and a weighted, uniformly locally finite graph. In his paper "Parabolic Harnack inequality and estimates of Markov chains on graphs", Delmotte proves that parabolic Harnack...
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Magda Khalile (Leibniz Universität Hannover)
Abstract
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Marc Hellmuth (Universität Greifswald)
Phylogenomics aims at finding plausible hypothesis about the evolutionary history of gene or species based on genomic sequence information. Genes are passed from generation to generation to the...
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Florian Fischer (Universität Potsdam)
In the classical potential theory on Euclidean space and in the potential theory of transient Markov chains a unique decomposition of superharmonic functions in a harmonic and a potential part is...
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Christian Rose (Technische Universität Chemnitz)
We show that if the negative part of the Ricci curvature of a compact manifold is in the Kato-class, the Cheeger constant of the manifold can be bounded below by a positive constant. This is obtained...
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Siegfried Beckus (Universität Potsdam)
The celebrated Shnol theorem asserts that every polynomially bounded generalized eigenfunction for a given energy E associated with a Schrödinger operator H implies that E is in the L2-spectrum of H....
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Melchior Wirth
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Michael Hinz (Bielefeld)
In this talk we review the definitions of items of vector calculus based on Dirichlet forms and mention connections to graph Laplacians and to non-local and local operators on metric measure spaces....
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Dorothee Schüth (HU Berlin)
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Jan Maas (IST Austria)
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Michael Schwarz
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Florentin Münch
We give rigidity results for discrete Bonnet-Myers diameter bound and Lichnerowicz eigenvalue estimate. Both inequalities are sharp if and only if the underlying graph is a hypercube. The proofs use...
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Moritz Gerlach
This talk aims at completing the picture how exactness of dynamical systems is related to the asymptotic behavior of the Perron-Frobenius operator. In doing so, we give a mixing-like description of...
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Felix Pogorzelski (Technion Haifa)
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Radoslaw Wojciechowski (CUNY)
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Shiping Liu (Durham)
I will discuss a Buser type and a Lichnerowicz type eigenvalue estimates for the magnetic Laplacian on a closed Riemannian manifold. Those are motivated by our previous ...
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Christian Seifert (Hamburg Harburg)
We consider families of bounded linear operators on \ell_p-spaces of discrete groups, parametrized by a dynamical system. By using limit operator techniques, we show that all the operators from that...
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Markus Kunze (Konstanz)
We consider diffusion problems in a domain which is further subdivided by semi-permeable membranes. Such problems frequently occur in applications in biology, for example when studying the...
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Martin Schuhmacher
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Felix Knöppel (TU Berlin)
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Batu Güneysu (HU Berlin)
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Elke Rosenberger (Potsdam)
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Siegfried Beckus (University Jena)
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Christian Rose (TU Chemnitz)
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Michela Egidi (TU Chemnitz)
In this talk (joint work with O. Post) we consider a family of compact, oriented and connected n-dimensional manifolds constructed according to the ...
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Francesco Tudisco (Saarland University)
This introductory talk will focus on the eigenvalues and eigenfunctions of the graph p-Laplacian. We shall discuss two definitions of the eigenpairs that come as a natural generalization of the linear...
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Jochen Glück (Universität Ulm)
Let T = (T(t)) be a C_0-semigroup on some function space or, more generally, on a Banach lattice E. The semigroup T is called positive if T(t)f \ge 0 for each 0 \le f \in E and for each t \geg 0....
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Jun Masamune (Tohoku University)
When every harmonic function belonging to a space $E$ of functions is identically constant, we say that the $E$-Liouville property holds true. There are different types of Liouville property according...
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Felix Pogorzelski (Technion Haifa)
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Marcel Schmidt (University Jena)
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Michael Schwarz (Potsdam)
We consider weighted graphs with an infinite set $X$ of vertices such that every function of finite energy is bounded. For each of these graphs there is a compact set $K$ containing $X$ as a dense...
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Florentin Münch (Potsdam)
We introduce a new version of curvature dimension inequality. We use this to prove a logarithmic Li-Yau inequality on graphs. To formulate this inequality, we use a non-linear ariant of the calculus...
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Moritz Gerlach (Potsdam)
Given a finite sequence of n samples drawn independently at random from a compact submanifold of the Euclidean space, we study the asymptotic behavior of Laplacians on the epsilon-neighborhood graph...
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