{"id":641,"date":"2019-01-21T09:31:51","date_gmt":"2019-01-21T07:31:51","guid":{"rendered":"https:\/\/yrmath4.conf.uoi.gr\/?page_id=641"},"modified":"2026-05-05T09:58:36","modified_gmt":"2026-05-05T07:58:36","slug":"invited-speakers","status":"publish","type":"page","link":"https:\/\/yrmath4.conf.uoi.gr\/?page_id=641","title":{"rendered":"Invited Speakers"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"641\" class=\"elementor elementor-641\" data-elementor-settings=\"[]\">\n\t\t\t<div class=\"elementor-inner\">\n\t\t\t\t<div class=\"elementor-section-wrap\">\n\t\t\t\t\t\t\t<section class=\"elementor-element elementor-element-63b6edf elementor-section-stretched elementor-section-full_width elementor-section-content-middle elementor-section-height-default elementor-section-height-default elementor-section elementor-top-section\" data-id=\"63b6edf\" data-element_type=\"section\" data-settings=\"{&quot;stretch_section&quot;:&quot;section-stretched&quot;,&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t<div class=\"elementor-row\">\n\t\t\t\t<div class=\"elementor-element elementor-element-bfd4c27 elementor-column elementor-col-100 elementor-top-column\" data-id=\"bfd4c27\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-element elementor-element-95a5a5c elementor-section-boxed elementor-section-height-default elementor-section-height-default elementor-section elementor-top-section\" data-id=\"95a5a5c\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t<div class=\"elementor-row\">\n\t\t\t\t<div class=\"elementor-element elementor-element-202da4c elementor-column elementor-col-100 elementor-top-column\" data-id=\"202da4c\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e067276 elementor-widget elementor-widget-heading\" data-id=\"e067276\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Invited Speakers<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-element elementor-element-26c6035 elementor-section-boxed elementor-section-height-default elementor-section-height-default elementor-invisible elementor-section elementor-top-section\" data-id=\"26c6035\" data-element_type=\"section\" data-settings=\"{&quot;animation&quot;:&quot;fadeInDown&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t<div class=\"elementor-row\">\n\t\t\t\t<div class=\"elementor-element elementor-element-22930dc elementor-column elementor-col-50 elementor-top-column\" data-id=\"22930dc\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-f571de0 elementor-position-top elementor-vertical-align-top elementor-widget elementor-widget-image-box\" data-id=\"f571de0\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img width=\"150\" height=\"150\" src=\"https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/2025\/10\/Giannopoulos-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" decoding=\"async\" loading=\"lazy\" \/><\/figure><\/div>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c7480c0 elementor-widget elementor-widget-text-editor\" data-id=\"c7480c0\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fd293c4 elementor-column elementor-col-50 elementor-top-column\" data-id=\"fd293c4\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-4e8e6dc elementor-widget elementor-widget-text-editor\" data-id=\"4e8e6dc\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><ul><li style=\"text-align: left;\"><span style=\"font-family: Verdana, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;\"><span class=\"contact-name\"><strong><a href=\"https:\/\/sites.google.com\/view\/apgiannop\/home?authuser=0\">Apostolos Giannopoulos,\u00a0<\/a><\/strong>School of Applied Mathematical and Physical Sciences, National Technical University of Athens<br \/><\/span><\/span><strong><br \/>\u03a4itle:<\/strong>Functional perimeter and the dimensional Brunn-Minkowski inequality for log-concave measures.<br \/><strong><strong><strong>Abstract: <\/strong><\/strong><\/strong>We study the dimensional Brunn&#8211;Minkowski inequality for even log-concave probability measures $\\mu$ on $\\mathbb{R}^n$ via an analytic approach based on diffusion operators and gradient estimates. Our main result asserts that for every pair of symmetric convex sets $K,L$ in $\\mathbb{R}^n$ and every $\\lambda\\in(0,1)$, $\\mu(\\lambda K+(1-\\lambda)L)^{c_n} \\geq \\lambda \\mu(K)^{c_n}+(1-\\lambda)\\mu(L)<wbr \/>^{c_n}, $\u00a0where $c_n\\geq c\/n^3\\ln n$ for some universal constant $c&gt;0$. A key ingredient in our proof is the bound\u00a0$\\int_{\\mathbb{R}^n} |\\nabla\\psi|\\,d\\mu \\leq Cn$\u00a0that we establish \u00a0for isotropic log-concave probability measures $\\mu$ on $\\mathbb{R}^n$ with density $e^{-\\psi}$, which is optimal in terms of the dimension. This estimate yields structural information on the size of sub-level sets of the gradient of $\\psi$ and puts forth a geometric obstruction to further improvements of the Brunn&#8211;Minkowski exponent. We also present applications of this estimate to the weighted perimeter of level sets, projections, moment and surface area measures of isotropic log-concave functions, highlighting the central role of the gradient of the logarithmic potential in high-dimensional convexity.<p>The talk is based on joint work with Alexandros Eskenazis and Natalia Tziotziou.<\/p><hr \/><\/li><\/ul><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-element elementor-element-ee2a551 elementor-section-boxed elementor-section-height-default elementor-section-height-default elementor-invisible elementor-section elementor-top-section\" data-id=\"ee2a551\" data-element_type=\"section\" data-settings=\"{&quot;animation&quot;:&quot;fadeInDown&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t<div class=\"elementor-row\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ca80770 elementor-column elementor-col-50 elementor-top-column\" data-id=\"ca80770\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-738cafb elementor-position-top elementor-vertical-align-top elementor-widget elementor-widget-image-box\" data-id=\"738cafb\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img width=\"150\" height=\"150\" src=\"https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/2025\/10\/karlis-150x150.jpg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" decoding=\"async\" loading=\"lazy\" srcset=\"https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/2025\/10\/karlis-150x150.jpg 150w, https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/2025\/10\/karlis-300x300.jpg 300w, https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/2025\/10\/karlis.jpg 400w\" sizes=\"(max-width: 150px) 100vw, 150px\" \/><\/figure><\/div>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f54f1d9 elementor-widget elementor-widget-text-editor\" data-id=\"f54f1d9\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6c288c5 elementor-column elementor-col-50 elementor-top-column\" data-id=\"6c288c5\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9676c84 elementor-widget elementor-widget-text-editor\" data-id=\"9676c84\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><ul><li style=\"text-align: left;\"><strong><a href=\"https:\/\/www.aueb.gr\/en\/faculty_page\/karlis-dimitrios\">Dimitris Karlis,\u00a0<\/a><\/strong>Dept. of Statistics, Athens University of Economics and Business (AUEB)<p><strong><br \/>Title: <\/strong>Random Coefficient extensions for integer autoregressive models: a non-parametric approach.<span style=\"font-size: 16px;\"><b><br \/><\/b><\/span><strong>Abstract:<\/strong> In this talk, we use the class of integer autoregressive (INAR) time series models, widely used to model time series of counts. INAR models extend the idea of classical time series for continuous data in an admissible way to keep the discrete nature of the data. Random Coefficient INteger AutoRegressive (RCINAR) models constitute an important extension of the simple INAR model when the thinning parameters are considered to be random. In the present paper, we propose the case that the thinning parameter follows a discrete distribution with positive probability at a finite number of points. We do not specify any parametric family for the distribution.\u00a0 We provide an EM algorithm to estimate the model while we link the model to the non-parametric Maximum Likelihood estimate of the mixing distribution. The ideas are then extended to the bivariate case where the thinning parameters are now a matrix of random variables. The finite mixture representation helps a lot to account for the extra variability but also extra correlation to the model.<\/p><hr \/><\/li><\/ul><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-element elementor-element-dd191e6 elementor-section-boxed elementor-section-height-default elementor-section-height-default elementor-invisible elementor-section elementor-top-section\" data-id=\"dd191e6\" data-element_type=\"section\" data-settings=\"{&quot;animation&quot;:&quot;fadeInDown&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t<div class=\"elementor-row\">\n\t\t\t\t<div class=\"elementor-element elementor-element-056baa2 elementor-column elementor-col-50 elementor-top-column\" data-id=\"056baa2\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1399f23 elementor-position-top elementor-vertical-align-top elementor-widget elementor-widget-image-box\" data-id=\"1399f23\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img decoding=\"async\" src=\"https:\/\/yrmath4.conf.uoi.gr\/wp-content\/uploads\/elementor\/thumbs\/platis-rdtcls4qrbfbs93ctddid129yy08l2hadhdh4v8if4.jpg\" title=\"platis\" alt=\"platis\" \/><\/figure><\/div>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c823688 elementor-widget elementor-widget-text-editor\" data-id=\"c823688\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f09f8be elementor-column elementor-col-50 elementor-top-column\" data-id=\"f09f8be\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-column-wrap  elementor-element-populated\">\n\t\t\t\t\t<div class=\"elementor-widget-wrap\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b049c33 elementor-widget elementor-widget-text-editor\" data-id=\"b049c33\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-text-editor elementor-clearfix\"><ul><li style=\"text-align: left;\"><strong><a href=\"https:\/\/thalis.math.upatras.gr\/~idplatis\/\">Ioannis Platis, <\/a><\/strong>Department of Mathematics, University of Patras<p><strong><br \/>Title:<\/strong> Horizontal curvatures of surfaces in 3-dimensional, contact sub-Riemannian Lie groups.<strong style=\"font-size: 16px;\"><br \/><\/strong><strong>Abstract:<\/strong> In this talk we study horizontal curvatures for surfaces embedded in three-dimensional<br \/>contact sub-Riemannian Lie groups. Using a Riemannian approximation scheme, we are able to derive explicit formulas for horizontal Gauss curvature, horizontal mean curvature, and symplectic distortion for<br \/>surfaces embedded in three dimensional Lie groups with a sub-Riemannian structure obtained by<br \/>a contact form. We focus on two primary examples: the Heisenberg group and the affine-additive<br \/>group. We classify surfaces of revolution within these groups that exhibit constant horizontal<br \/>curvatures, often expressing their profiles through elementary or elliptic integrals.<\/p><hr \/><\/li><\/ul><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Invited Speakers Apostolos Giannopoulos,\u00a0School of Applied Mathematical and Physical Sciences, National Technical University of Athens\u03a4itle:Functional perimeter and the dimensional Brunn-Minkowski inequality for log-concave measures.Abstract: We study the dimensional Brunn&#8211;Minkowski inequality for even log-concave probability measures $mu$ on $mathbb{R}^n$ via an analytic approach based on diffusion operators and gradient estimates. Our main result asserts that for [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/pages\/641"}],"collection":[{"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=641"}],"version-history":[{"count":22,"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/pages\/641\/revisions"}],"predecessor-version":[{"id":2794,"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=\/wp\/v2\/pages\/641\/revisions\/2794"}],"wp:attachment":[{"href":"https:\/\/yrmath4.conf.uoi.gr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=641"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}