0000000000154347

AUTHOR

Timo Schultz

showing 6 related works from this author

Optimal transport maps on Alexandrov spaces revisited

2018

We give an alternative proof for the fact that in $n$-dimensional Alexandrov spaces with curvature bounded below there exists a unique optimal transport plan from any purely $(n-1)$-unrectifiable starting measure, and that this plan is induced by an optimal map.

Mathematics - Differential GeometryClass (set theory)Pure mathematicsGeneral MathematicsExistential quantificationPlan (drawing)Algebraic geometryoptimaalisuusCurvatureMeasure (mathematics)Primary 53C23. Secondary 49K30Mathematics - Analysis of PDEsMathematics - Metric GeometryFOS: Mathematicsmass transportationMathematics::Metric GeometryMathematicsAlexandrov-avaruudetMetric Geometry (math.MG)Number theoryDifferential Geometry (math.DG)Bounded functionMathematics::Differential GeometrymassasiirtoAlexandrov spacesAnalysis of PDEs (math.AP)
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Existence of optimal transport maps in very strict CD(K,∞) -spaces

2018

We introduce a more restrictive version of the strict CD(K,∞) -condition, the so-called very strict CD(K,∞) -condition, and show the existence of optimal maps in very strict CD(K,∞) -spaces despite the possible lack of uniqueness of optimal plans. peerReviewed

metric measure spacesdifferentiaaligeometriaRicci curvatureoptimal mass transportationvariaatiolaskentaexistence of optimal mapsmittateoriametriset avaruudetbranching geodesics
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Pintojen perusryhmistä

2015

Tässä tutkielmassa osoitetaan ennestään tunnettu pintoihin liittyvä tulos, jonka mukaan epäkompaktin pinnan perusryhmä on vapaa. Todistus pohjautuu tietoon siitä, että jokaisella pinnalla on olemassa niin sanottu kolmiointi. Pinnan kolmiointia hyödyntäen pinta tyhjennetään sopivilla sisäkkäisillä kompakteilla reunallisilla pinnoilla siten, että pinnan perus ryhmä saadaan näiden kompaktien reunallisten pintojen sisäkkäisten pe rusryhmien yhdisteenä. Kompakti reunallinen pinta osoitetaan homotopia ekvivalentiksi graafin kanssa deformaatioretraktoimalla reunallinen pinta graafiksi reunallisen pinnan kolmiointia hyödyntäen. Koska homotopiaekvi valenttien avaruuksien perusryhmät ovat isomorfiset…

pintahomotopiapinnatgraafivapaa ryhmätopologiaalgebrallinen topologiaryhmätgraafitperusryhmä
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A Density Result for Homogeneous Sobolev Spaces on Planar Domains

2018

We show that in a bounded simply connected planar domain $\Omega$ the smooth Sobolev functions $W^{k,\infty}(\Omega)\cap C^\infty(\Omega)$ are dense in the homogeneous Sobolev spaces $L^{k,p}(\Omega)$.

Pure mathematicsMathematics::Analysis of PDEs01 natural sciencesPotential theoryDomain (mathematical analysis)010104 statistics & probabilityPlanartiheysSimply connected spaceClassical Analysis and ODEs (math.CA)FOS: Mathematics46E350101 mathematicsMathematicsMathematics::Functional AnalysisFunctional analysis010102 general mathematicshomogeneous Sobolev spaceSobolev spaceFunctional Analysis (math.FA)Sobolev spaceMathematics - Functional AnalysisHomogeneousMathematics - Classical Analysis and ODEsBounded functionAnalysis
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On one-dimensionality of metric measure spaces

2019

In this paper, we prove that a metric measure space which has at least one open set isometric to an interval, and for which the (possibly non-unique) optimal transport map exists from any absolutely continuous measure to an arbitrary measure, is a one-dimensional manifold (possibly with boundary). As an immediate corollary we obtain that if a metric measure space is a very strict $CD(K,N)$ -space or an essentially non-branching $MCP(K,N)$-space with some open set isometric to an interval, then it is a one-dimensional manifold. We also obtain the same conclusion for a metric measure space which has a point in which the Gromov-Hausdorff tangent is unique and isometric to the real line, and fo…

metric measure spacesMathematics - Differential GeometryApplied MathematicsGeneral MathematicsOpen setBoundary (topology)Metric Geometry (math.MG)Space (mathematics)53C23Measure (mathematics)metriset avaruudetManifoldCombinatoricsdifferentiaaligeometriaRicci curvatureDifferential Geometry (math.DG)optimal transportMathematics - Metric GeometryMetric (mathematics)FOS: MathematicsmittateoriaGromov--Hausdorff tangentsReal lineRicci curvatureMathematics
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Equivalent definitions of very strict $CD(K,N)$ -spaces

2023

We show the equivalence of the definitions of very strict $CD(K,N)$ -condition defined, on one hand, using (only) the entropy functionals, and on the other, the full displacement convexity class $\mathcal{DC}_N$. In particular, we show that assuming the convexity inequalities for the critical exponent implies it for all the greater exponents. We also establish the existence of optimal transport maps in very strict $CD(K,N)$ -spaces with finite $N$.

Mathematics - Differential Geometrymetric measure spacesdifferentiaaligeometriaRicci curvatureMathematics - Metric Geometryoptimal transportDifferential Geometry (math.DG)Optimal transportFOS: MathematicsMetric Geometry (math.MG)Geometry and Topology53C23Metric measure spaces
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