@article{18632, abstract = {For an arbitrary dimension (Formula presented.), we study: the polyharmonic Gaussian field (Formula presented.) on the discrete torus (Formula presented.), that is the random field whose law on (Formula presented.) given by (Formula presented.) where (Formula presented.) is the Lebesgue measure and (Formula presented.) is the discrete Laplacian; the associated discrete Liouville quantum gravity (LQG) measure associated with it, that is, the random measure on (Formula presented.) (Formula presented.) where (Formula presented.) is a regularity parameter. As (Formula presented.), we prove convergence of the fields (Formula presented.) to the polyharmonic Gaussian field (Formula presented.) on the continuous torus (Formula presented.), as well as convergence of the random measures (Formula presented.) to the LQG measure (Formula presented.) on (Formula presented.), for all (Formula presented.). }, author = {Dello Schiavo, Lorenzo and Herry, Ronan and Kopfer, Eva and Sturm, Karl Theodor}, issn = {1522-2616}, journal = {Mathematische Nachrichten}, number = {1}, pages = {244--281}, publisher = {Wiley}, title = {{Polyharmonic fields and Liouville quantum gravity measures on tori of arbitrary dimension: From discrete to continuous}}, doi = {10.1002/mana.202400169}, volume = {298}, year = {2025}, } @article{14934, abstract = {We study random perturbations of a Riemannian manifold (M, g) by means of so-called Fractional Gaussian Fields, which are defined intrinsically by the given manifold. The fields h• : ω → hω will act on the manifold via the conformal transformation g → gω := e2hω g. Our focus will be on the regular case with Hurst parameter H > 0, the critical case H = 0 being the celebrated Liouville geometry in two dimensions. We want to understand how basic geometric and functional-analytic quantities like diameter, volume, heat kernel, Brownian motion, spectral bound, or spectral gap change under the influence of the noise. And if so, is it possible to quantify these dependencies in terms of key parameters of the noise? Another goal is to define and analyze in detail the Fractional Gaussian Fields on a general Riemannian manifold, a fascinating object of independent interest.}, author = {Dello Schiavo, Lorenzo and Kopfer, Eva and Sturm, Karl Theodor}, issn = {1572-929X}, journal = {Potential Analysis}, pages = {501--553}, publisher = {Springer Nature}, title = {{A discovery tour in random Riemannian geometry}}, doi = {10.1007/s11118-023-10118-0}, volume = {61}, year = {2024}, } @article{15252, abstract = {A measurable map between measure spaces is shown to have bounded compression if and only if its image via the measure-algebra functor is Lipschitz-continuous w.r.t. the measure-algebra distances. This provides a natural interpretation of maps of bounded compression/deformation by means of the measure-algebra functor and corrobo-rates the assertion that maps of bounded deformation are a natural class of morphisms for the category of complete and separable metric measure spaces.}, author = {Dello Schiavo, Lorenzo}, issn = {1848-8013}, journal = {Mathematical Communications}, number = {1}, pages = {137--142}, publisher = {Udruga Matematicara Osijek}, title = {{A characterization of maps of bounded compression}}, volume = {29}, year = {2024}, } @article{15317, abstract = {We consider the open symmetric exclusion (SEP) and inclusion (SIP) processes on a bounded Lipschitz domain Ω, with both fast and slow boundary. For the random walks on Ω dual to SEP/SIP we establish: a functional-CLT-type convergence to the Brownian motion on Ω with either Neumann (slow boundary), Dirichlet (fast boundary), or Robin (at criticality) boundary conditions; the discrete-to-continuum convergence of the corresponding harmonic profiles. As a consequence, we rigorously derive the hydrodynamic and hydrostatic limits for SEP/SIP on Ω, and analyze their stationary nonequilibrium fluctuations. All scaling limit results for SEP/SIP concern finite-dimensional distribution convergence only, as our duality techniques do not require to establish tightness for the fields associated to the particle systems.}, author = {Dello Schiavo, Lorenzo and Portinale, Lorenzo and Sau, Federico}, issn = {1050-5164}, journal = {Annals of Applied Probability}, number = {2}, pages = {1789--1845}, publisher = {Institute of Mathematical Statistics}, title = {{Scaling limits of random walks, harmonic profiles, and stationary nonequilibrium states in Lipschitz domains}}, doi = {10.1214/23-AAP2007}, volume = {34}, year = {2024}, } @article{17143, abstract = {This paper deals with local criteria for the convergence to a global minimiser for gradient flow trajectories and their discretisations. To obtain quantitative estimates on the speed of convergence, we consider variations on the classical Kurdyka–Łojasiewicz inequality for a large class of parameter functions. Our assumptions are given in terms of the initial data, without any reference to an equilibrium point. The main results are convergence statements for gradient flow curves and proximal point sequences to a global minimiser, together with sharp quantitative estimates on the speed of convergence. These convergence results apply in the general setting of lower semicontinuous functionals on complete metric spaces, generalising recent results for smooth functionals on Rn. While the non-smooth setting covers very general spaces, it is also useful for (non)-smooth functionals on Rn. .}, author = {Dello Schiavo, Lorenzo and Maas, Jan and Pedrotti, Francesco}, issn = {1088-6850}, journal = {Transactions of the American Mathematical Society}, number = {6}, pages = {3779--3804}, publisher = {American Mathematical Society}, title = {{Local conditions for global convergence of gradient flows and proximal point sequences in metric spaces}}, doi = {10.1090/tran/9156}, volume = {377}, year = {2024}, } @article{18490, abstract = {For large classes of even-dimensional Riemannian manifolds (Formula presented.), we construct and analyze conformally invariant random fields. These centered Gaussian fields (Formula presented.), called co-polyharmonic Gaussian fields, are characterized by their covariance kernels k which exhibit a precise logarithmic divergence: (Formula presented.). They share a fundamental quasi-invariance property under conformal transformations. In terms of the co-polyharmonic Gaussian field (Formula presented.), we define the Liouville Quantum Gravity measure, a random measure on (Formula presented.), heuristically given as (Formula presented.) and rigorously obtained as almost sure weak limit of the right-hand side with (Formula presented.) replaced by suitable regular approximations (Formula presented.). In terms on the Liouville Quantum Gravity measure, we define the Liouville Brownian motion on (Formula presented.) and the random GJMS operators. Finally, we present an approach to a conformal field theory in arbitrary even dimension with an ansatz based on Branson's (Formula presented.) -curvature: we give a rigorous meaning to the Polyakov–Liouville measure (Formula presented.) and we derive the corresponding conformal anomaly. The set of admissible manifolds is conformally invariant. It includes all compact 2-dimensional Riemannian manifolds, all compact non-negatively curved Einstein manifolds of even dimension, and large classes of compact hyperbolic manifolds of even dimension. However, not every compact even-dimensional Riemannian manifold is admissible. Our results concerning the logarithmic divergence of the kernel (Formula presented.) rely on new sharp estimates for heat kernels and higher order Green kernels on arbitrary closed manifolds. }, author = {Dello Schiavo, Lorenzo and Herry, Ronan and Kopfer, Eva and Sturm, Karl Theodor}, issn = {1469-7750}, journal = {Journal of the London Mathematical Society}, number = {5}, publisher = {London Mathematical Society}, title = {{Conformally invariant random fields, Liouville quantum gravity measures, and random Paneitz operators on Riemannian manifolds of even dimension}}, doi = {10.1112/jlms.70003}, volume = {110}, year = {2024}, } @article{18158, abstract = {We study the geometry of Poisson point processes from the point of view of optimal transport and Ricci lower bounds. We construct a Riemannian structure on the space of point processes and the associated distance W that corresponds to the Benamou–Brenier variational formula. Our main tool is a non-local continuity equation formulated with the difference operator. The closure of the domain of the relative entropy is a complete geodesic space, when endowed with W. The geometry of this non-local infinite-dimensional space is analogous to that of spaces with positive Ricci curvature. Among others: (a) the Ornstein–Uhlenbeck semi-group is the gradient flow of the relative entropy; (b) the Poisson space has an entropic Ricci curvature bounded from below by 1; (c) W satisfies an HWI inequality.}, author = {Dello Schiavo, Lorenzo and Herry, Ronan and Suzuki, Kohei}, issn = {2270-518X}, journal = {Journal de l'Ecole Polytechnique - Mathematiques}, pages = {957--1010}, publisher = {Ecole Polytechnique}, title = {{Wasserstein geometry and Ricci curvature bounds for Poisson spaces}}, doi = {10.5802/jep.270}, volume = {11}, year = {2024}, } @article{12104, abstract = {We study ergodic decompositions of Dirichlet spaces under intertwining via unitary order isomorphisms. We show that the ergodic decomposition of a quasi-regular Dirichlet space is unique up to a unique isomorphism of the indexing space. Furthermore, every unitary order isomorphism intertwining two quasi-regular Dirichlet spaces is decomposable over their ergodic decompositions up to conjugation via an isomorphism of the corresponding indexing spaces.}, author = {Dello Schiavo, Lorenzo and Wirth, Melchior}, issn = {1424-3202}, journal = {Journal of Evolution Equations}, number = {1}, publisher = {Springer Nature}, title = {{Ergodic decompositions of Dirichlet forms under order isomorphisms}}, doi = {10.1007/s00028-022-00859-7}, volume = {23}, year = {2023}, } @article{13145, abstract = {We prove a characterization of the Dirichlet–Ferguson measure over an arbitrary finite diffuse measure space. We provide an interpretation of this characterization in analogy with the Mecke identity for Poisson point processes.}, author = {Dello Schiavo, Lorenzo and Lytvynov, Eugene}, issn = {1083-589X}, journal = {Electronic Communications in Probability}, pages = {1--12}, publisher = {Institute of Mathematical Statistics}, title = {{A Mecke-type characterization of the Dirichlet–Ferguson measure}}, doi = {10.1214/23-ECP528}, volume = {28}, year = {2023}, } @unpublished{20572, abstract = {We present an elementary non-recursive formula for the multivariate moments of the Dirichlet distribution on the standard simplex, in terms of the pattern inventory of the moments' exponents. We obtain analog formulas for the multivariate moments of the Dirichlet-Ferguson and Gamma measures. We further introduce a polychromatic analogue of Ewens sampling formula on colored integer partitions, discuss its relation with suitable extensions of Hoppe's urn model and of the Chinese restaurant process, and prove that it satisfies an adapted notion of consistency in the sense of Kingman.}, author = {Dello Schiavo, Lorenzo and Quattrocchi, Filippo}, booktitle = {arXiv}, keywords = {Dirichlet distribution, Ewens sampling formula, Hoppe urn model, colored partitions}, title = {{Multivariate Dirichlet moments and a polychromatic Ewens sampling formula}}, doi = {10.48550/arXiv.2309.11292}, year = {2023}, } @article{10145, abstract = {We study direct integrals of quadratic and Dirichlet forms. We show that each quasi-regular Dirichlet space over a probability space admits a unique representation as a direct integral of irreducible Dirichlet spaces, quasi-regular for the same underlying topology. The same holds for each quasi-regular strongly local Dirichlet space over a metrizable Luzin σ-finite Radon measure space, and admitting carré du champ operator. In this case, the representation is only projectively unique.}, author = {Dello Schiavo, Lorenzo}, issn = {1572-929X}, journal = {Potential Analysis}, pages = {573--615}, publisher = {Springer Nature}, title = {{Ergodic decomposition of Dirichlet forms via direct integrals and applications}}, doi = {10.1007/s11118-021-09951-y}, volume = {58}, year = {2023}, } @article{11354, abstract = {We construct a recurrent diffusion process with values in the space of probability measures over an arbitrary closed Riemannian manifold of dimension d≥2. The process is associated with the Dirichlet form defined by integration of the Wasserstein gradient w.r.t. the Dirichlet–Ferguson measure, and is the counterpart on multidimensional base spaces to the modified massive Arratia flow over the unit interval described in V. Konarovskyi and M.-K. von Renesse (Comm. Pure Appl. Math. 72 (2019) 764–800). Together with two different constructions of the process, we discuss its ergodicity, invariant sets, finite-dimensional approximations, and Varadhan short-time asymptotics.}, author = {Dello Schiavo, Lorenzo}, issn = {2168-894X}, journal = {Annals of Probability}, number = {2}, pages = {591--648}, publisher = {Institute of Mathematical Statistics}, title = {{The Dirichlet–Ferguson diffusion on the space of probability measures over a closed Riemannian manifold}}, doi = {10.1214/21-AOP1541}, volume = {50}, year = {2022}, } @article{12177, abstract = {Using elementary hyperbolic geometry, we give an explicit formula for the contraction constant of the skinning map over moduli spaces of relatively acylindrical hyperbolic manifolds.}, author = {Cremaschi, Tommaso and Dello Schiavo, Lorenzo}, issn = {2330-1511}, journal = {Proceedings of the American Mathematical Society, Series B}, number = {43}, pages = {445--459}, publisher = {American Mathematical Society}, title = {{Effective contraction of Skinning maps}}, doi = {10.1090/bproc/134}, volume = {9}, year = {2022}, } @article{10588, abstract = {We prove the Sobolev-to-Lipschitz property for metric measure spaces satisfying the quasi curvature-dimension condition recently introduced in Milman (Commun Pure Appl Math, to appear). We provide several applications to properties of the corresponding heat semigroup. In particular, under the additional assumption of infinitesimal Hilbertianity, we show the Varadhan short-time asymptotics for the heat semigroup with respect to the distance, and prove the irreducibility of the heat semigroup. These results apply in particular to large classes of (ideal) sub-Riemannian manifolds.}, author = {Dello Schiavo, Lorenzo and Suzuki, Kohei}, issn = {1432-1807}, journal = {Mathematische Annalen}, keywords = {quasi curvature-dimension condition, sub-riemannian geometry, Sobolev-to-Lipschitz property, Varadhan short-time asymptotics}, pages = {1815--1832}, publisher = {Springer Nature}, title = {{Sobolev-to-Lipschitz property on QCD- spaces and applications}}, doi = {10.1007/s00208-021-02331-2}, volume = {384}, year = {2022}, } @article{10070, abstract = {We extensively discuss the Rademacher and Sobolev-to-Lipschitz properties for generalized intrinsic distances on strongly local Dirichlet spaces possibly without square field operator. We present many non-smooth and infinite-dimensional examples. As an application, we prove the integral Varadhan short-time asymptotic with respect to a given distance function for a large class of strongly local Dirichlet forms.}, author = {Dello Schiavo, Lorenzo and Suzuki, Kohei}, issn = {1096-0783}, journal = {Journal of Functional Analysis}, number = {11}, publisher = {Elsevier}, title = {{Rademacher-type theorems and Sobolev-to-Lipschitz properties for strongly local Dirichlet spaces}}, doi = {10.1016/j.jfa.2021.109234}, volume = {281}, year = {2021}, }