{"id":199649,"date":"2009-01-07T10:41:09","date_gmt":"2009-01-07T18:41:09","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/research\/events\/northwest-probability-seminar\/"},"modified":"2022-08-31T12:56:58","modified_gmt":"2022-08-31T19:56:58","slug":"northwest-probability-seminar","status":"publish","type":"msr-event","link":"https:\/\/www.microsoft.com\/en-us\/research\/event\/northwest-probability-seminar\/","title":{"rendered":"Northwest Probability Seminar 2008"},"content":{"rendered":"\n\n\n\n\n<p>This is a recap of the&nbsp;tenth Northwest Probability Seminar&nbsp;was a one-day mini-conference organized by the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/\">University of Washington<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>, the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/math.oregonstate.edu\/\">Oregon State University<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>, the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.ubc.ca\/\">University of British Columbia<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>, the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/math.uoregon.edu\/\">University of Oregon<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>, and the <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/group\/theory-group\/\">Theory Group<\/a> at <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\">Microsoft Research<\/a>. Usually the conference is hosted at the University of Washington, but this year the conference&nbsp;was hosted at Microsoft.<\/p>\n<p>Supported by the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.msri.org\/\"><b>Mathematical Sciences Research Institute<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (MSRI),<br>\n<a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\"><b>Microsoft Research<\/b><\/a>, and the <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/pims.math.ca\/\"><b>Pacific Institute for the Mathematical Sciences<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (PIMS).<\/p>\n<p>The <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~sheetz\/Obituaries\/zwbirnbaum.html\"><b>Birnbaum<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a><b> Lecture in Probability<\/b> was given by <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (Cornell). The other speakers were <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.ubc.ca\/~angel\/\">Omer Angel<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (UBC), Eyal Lubetzky (MSR), <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~soumik\/\">Soumik Pal<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (UW), and <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\">Edward Waymire<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (OSU).<\/p>\n<p>[<a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~burdzy\/nwprob2008photos.php\">Speaker photographs<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>] [<a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~burdzy\/birnbaumspeakers.php\">Past Birnbaum speakers<span class=\"sr-only\"> (opens in new tab)<\/span><\/a>]<\/p>\n<p>The Scientific Committee for the 2008 NW Probability Seminar consisted of <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.ubc.ca\/~barlow\/\">Martin Barlow<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (U British Columbia), <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~burdzy\/\">Chris Burdzy<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (U Washington), <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~zchen\/\">Zhen-Qing Chen<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (U Washington), <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.oregonstate.edu\/people\/view\/kovchegy\">Yevgeniy Kovchegov<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (Oregon State U), <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/darkwing.uoregon.edu\/~dlevin\/\">David Levin<span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (U Oregon), and <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/people\/peres\/\">Yuval Peres<\/a> (Microsoft).<\/p>\n\n\n\n\n\n<p>9:30 <b>Coffee and muffins<\/b><\/p>\n<p>10:30 <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (Cornell)<\/p>\n<blockquote>\n<p>Behavior of Brownian motion on compact Lie groups as a function of dimension (e.g., on special orthogonal groups).<\/p>\n<p><em>Abstract:<\/em> The distribution of Brownian motion on a compact manifold converge to its equilibrium (the normalized volume measure). Quantitatively, for natural families of compact manifolds, this convergence depends on certain geometric properties. In this talk we will focus on compact Lie groups such as the family of special orthogonal groups and consider the convergence of Brownian motion as the dimension grows to infinity.<\/p>\n<\/blockquote>\n<p>11:30 <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.ubc.ca\/~angel\/\"><b>Omer Angel<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (UBC)<\/p>\n<blockquote>\n<p>Colouring Voronoi<\/p>\n<p><em>Abstract:<\/em> We consider the problem of colouring the planar map given by the Voronoi tessellation corresponding to a Poisson process in R^2. We seek colouring rules that are isometry invariant and are factors of the Poisson process. We prove that 6 colours suffice.<\/p>\n<\/blockquote>\n<blockquote>\n<p>Joint work with Itai Benjamini, Ori Gurel-Gurevich, Tom Meyerovitch, and Ron Peled.<\/p>\n<\/blockquote>\n<p>12:15 <b>Open problems and microtalks<\/b><\/p>\n<p>1:00 <b>Lunch <\/b>(catered)<\/p>\n<p>2:15 <b>Eyal Lubetzky<\/b> (MSR)<\/p>\n<blockquote>\n<p>Cutoff phenomena for random walks on random regular graphs<\/p>\n<p><em>Abstract:<\/em> The cutoff phenomenon describes a sharp transition in the convergence of a family of ergodic finite Markov chains to equilibrium. Many natural families of chains are conjectured to exhibit cutoff, yet establishing this fact is often extremely challenging. An important such family of chains is the random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>), a random <i>d<\/i>-regular graph on <i>n<\/i> vertices. Friedman determined the constant spectral gap of this class of chains for <i>d<\/i> fixed, implying a mixing-time of O(log <i>n)<\/i>. Durrett conjectured that the mixing time of the lazy random walk on a random 3-regular graph is <i>whp<\/i> (6+o(1))log<sub>2<\/sub> <i>n<\/i>, and Peres further conjectured that for any fixed <i>d<\/i> the simple random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) has cutoff <i>whp<\/i>.<\/p>\n<p>In this work we confirm the above conjectures, and establish cutoff in total-variation, its location and its optimal window, both for simple and for non-backtracking random walks on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>). Namely, for any fixed <i>d<\/i>, the <i>simple<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff at d\/(d-2) log<i><sub>d<\/sub><\/i><sub>-1<\/sub> <i>n<\/i> with window order sqrt{log <i>n<\/i>}. Surprisingly, the <i>non-backtracking<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff already at log<sub>d-1<\/sub> <i>n<\/i> with <i>constant<\/i> window order. We further extend these results to <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) for any <i>d<\/i>=<i>n<\/i><sup>o(1)<\/sup> (beyond which the mixing time is O(1)), provide efficient algorithms for testing cutoff, as well as give explicit constructions where cutoff occurs.<\/p>\n<p>Joint work with Allan Sly.<\/p>\n<\/blockquote>\n<p>3:00 <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.washington.edu\/~soumik\/\"><b>Soumik Pal<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (UW)<\/p>\n<blockquote>\n<p>Applications of a skew-product decomposition for the Bessel-Squared processes<\/p>\n<p><em>Abstract:<\/em> We consider different models arising in three distinct areas of probability: Watterson\u2019s Infinitely-Many-Neutral-Alleles model from mathematical biology, the Volatility-Stabilized-Market model of Fernholz and Karatzas in mathematical finance, and the embedding of large forests of critical Galton-Watson trees in Brownian motion. We show that all these models have a structure in which a skew-product decomposition of the Bessel-Squared processes play an important role. As a conclusion we see the emergence of a limiting Poisson-Dirichlet structure for each of them. For Watterson\u2019s model, this conclusion was proved earlier by Ethier and Kurtz via a different method. For the other models, these conclusions are new. In particular, we solve a problem posed by Fernholz and Karatzas with regards to the distribution of the \u2018market weights\u2019 functionals of the VSM model.<\/p>\n<\/blockquote>\n<p>3:45 <b>Tea<\/b><\/p>\n<p>4:15 <a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\"><b>Edward Waymire<\/b><span class=\"sr-only\"> (opens in new tab)<\/span><\/a> (OSU)<\/p>\n<blockquote>\n<p>Skew Brownian Motion and Applications in Fluid Dispersion<\/p>\n<p><em>Abstract:<\/em> Skew Brownian motion was introduced by Ito and Mckean in a classic 1963 paper devoted to constructions of various stochastic processes associated with Feller\u2019s classification of one-dimensional diffusions. Its basic properties and extensions have been the subject of a number of papers in the foundations of probability theory (many by probabilists in the Pacific Northwest !) In this talk we will discuss some recent and ongoing applications that arose out of discussions with colleagues in the geosciences at OSU. In particular this has led to the derivation of apparently new formulae for joint densities involving skew Brownian motion (with drift) and local and occupation times.<\/p>\n<p>It is based on joint work with OSU student and colleagues Thilanka Appuhamillage, Vrushali Bokil, Enrique Thomann, Brian Wood, and Jorge Ramirez (now at the University of Arizona).<\/p>\n<\/blockquote>\n<p>5:00 <b>Open problem solutions, conclude <\/b><\/p>\n<p>5:45 <b>Dinner<\/b> (not hosted)<\/p>\n<blockquote>\n<p><a class=\"msr-external-link glyph-append glyph-append-open-in-new-tab glyph-append-xsmall\" rel=\"noopener noreferrer\" target=\"_blank\" href=\"http:\/\/mattsrotisserie.com\/\">Matts\u2019 Rotisserie and Oyster Lounge<span class=\"sr-only\"> (opens in new tab)<\/span><\/a><\/p>\n<\/blockquote>\n\n\n","protected":false},"excerpt":{"rendered":"<p>This is a recap of the&nbsp;tenth Northwest Probability Seminar&nbsp;was a one-day mini-conference organized by the University of Washington (opens in new tab), the Oregon State University (opens in new tab), the University of British Columbia (opens in new tab), the University of Oregon (opens in new tab), and the Theory Group at Microsoft Research. Usually [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"_classifai_error":"","msr_startdate":"2008-11-08","msr_enddate":"2008-11-08","msr_location":"Redmond, WA","msr_expirationdate":"","msr_event_recording_link":"","msr_event_link":"","msr_event_link_redirect":false,"msr_event_time":"","msr_hide_region":false,"msr_private_event":true,"msr_hide_image_in_river":0,"footnotes":""},"research-area":[13561],"msr-region":[],"msr-event-type":[],"msr-video-type":[],"msr-locale":[268875],"msr-program-audience":[],"msr-post-option":[],"msr-impact-theme":[],"class_list":["post-199649","msr-event","type-msr-event","status-publish","hentry","msr-research-area-algorithms","msr-locale-en_us"],"msr_about":"<!-- wp:msr\/event-details {\"title\":\"Northwest Probability Seminar 2008\"} \/-->\n\n<!-- wp:msr\/content-tabs -->\n<!-- wp:msr\/content-tab {\"title\":\"Summary\"} -->\n<!-- wp:freeform -->\n<p>This is a recap of the&nbsp;tenth Northwest Probability Seminar&nbsp;was a one-day mini-conference organized by the <a href=\"http:\/\/www.math.washington.edu\/\">University of Washington<\/a>, the <a href=\"http:\/\/math.oregonstate.edu\/\">Oregon State University<\/a>, the <a href=\"http:\/\/www.math.ubc.ca\/\">University of British Columbia<\/a>, the <a href=\"http:\/\/math.uoregon.edu\/\">University of Oregon<\/a>, and the <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/group\/theory-group\/\">Theory Group<\/a> at <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\">Microsoft Research<\/a>. Usually the conference is hosted at the University of Washington, but this year the conference&nbsp;was hosted at Microsoft.<\/p>\n<p>Supported by the <a href=\"http:\/\/www.msri.org\/\"><b>Mathematical Sciences Research Institute<\/b><\/a> (MSRI),<br>\n<a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\"><b>Microsoft Research<\/b><\/a>, and the <a href=\"http:\/\/pims.math.ca\/\"><b>Pacific Institute for the Mathematical Sciences<\/b><\/a> (PIMS).<\/p>\n<p>The <a href=\"http:\/\/www.math.washington.edu\/~sheetz\/Obituaries\/zwbirnbaum.html\"><b>Birnbaum<\/b><\/a><b> Lecture in Probability<\/b> was given by <a href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><\/a> (Cornell). The other speakers were <a href=\"http:\/\/www.math.ubc.ca\/~angel\/\">Omer Angel<\/a> (UBC), Eyal Lubetzky (MSR), <a href=\"http:\/\/www.math.washington.edu\/~soumik\/\">Soumik Pal<\/a> (UW), and <a href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\">Edward Waymire<\/a> (OSU).<\/p>\n<p>[<a href=\"http:\/\/www.math.washington.edu\/~burdzy\/nwprob2008photos.php\">Speaker photographs<\/a>] [<a href=\"http:\/\/www.math.washington.edu\/~burdzy\/birnbaumspeakers.php\">Past Birnbaum speakers<\/a>]<\/p>\n<p>The Scientific Committee for the 2008 NW Probability Seminar consisted of <a href=\"http:\/\/www.math.ubc.ca\/~barlow\/\">Martin Barlow<\/a> (U British Columbia), <a href=\"http:\/\/www.math.washington.edu\/~burdzy\/\">Chris Burdzy<\/a> (U Washington), <a href=\"http:\/\/www.math.washington.edu\/~zchen\/\">Zhen-Qing Chen<\/a> (U Washington), <a href=\"http:\/\/www.math.oregonstate.edu\/people\/view\/kovchegy\">Yevgeniy Kovchegov<\/a> (Oregon State U), <a href=\"http:\/\/darkwing.uoregon.edu\/~dlevin\/\">David Levin<\/a> (U Oregon), and <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/people\/peres\/\">Yuval Peres<\/a> (Microsoft).<\/p>\n<!-- \/wp:freeform -->\n<!-- \/wp:msr\/content-tab -->\n\n<!-- wp:msr\/content-tab {\"title\":\"Schedule\"} -->\n<!-- wp:freeform -->\n<p>9:30 <b>Coffee and muffins<\/b><\/p>\n<p>10:30 <a href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><\/a> (Cornell)<\/p>\n<blockquote>\n<p>Behavior of Brownian motion on compact Lie groups as a function of dimension (e.g., on special orthogonal groups).<\/p>\n<p><em>Abstract:<\/em> The distribution of Brownian motion on a compact manifold converge to its equilibrium (the normalized volume measure). Quantitatively, for natural families of compact manifolds, this convergence depends on certain geometric properties. In this talk we will focus on compact Lie groups such as the family of special orthogonal groups and consider the convergence of Brownian motion as the dimension grows to infinity.<\/p>\n<\/blockquote>\n<p>11:30 <a href=\"http:\/\/www.math.ubc.ca\/~angel\/\"><b>Omer Angel<\/b><\/a> (UBC)<\/p>\n<blockquote>\n<p>Colouring Voronoi<\/p>\n<p><em>Abstract:<\/em> We consider the problem of colouring the planar map given by the Voronoi tessellation corresponding to a Poisson process in R^2. We seek colouring rules that are isometry invariant and are factors of the Poisson process. We prove that 6 colours suffice.<\/p>\n<\/blockquote>\n<blockquote>\n<p>Joint work with Itai Benjamini, Ori Gurel-Gurevich, Tom Meyerovitch, and Ron Peled.<\/p>\n<\/blockquote>\n<p>12:15 <b>Open problems and microtalks<\/b><\/p>\n<p>1:00 <b>Lunch <\/b>(catered)<\/p>\n<p>2:15 <b>Eyal Lubetzky<\/b> (MSR)<\/p>\n<blockquote>\n<p>Cutoff phenomena for random walks on random regular graphs<\/p>\n<p><em>Abstract:<\/em> The cutoff phenomenon describes a sharp transition in the convergence of a family of ergodic finite Markov chains to equilibrium. Many natural families of chains are conjectured to exhibit cutoff, yet establishing this fact is often extremely challenging. An important such family of chains is the random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>), a random <i>d<\/i>-regular graph on <i>n<\/i> vertices. Friedman determined the constant spectral gap of this class of chains for <i>d<\/i> fixed, implying a mixing-time of O(log <i>n)<\/i>. Durrett conjectured that the mixing time of the lazy random walk on a random 3-regular graph is <i>whp<\/i> (6+o(1))log<sub>2<\/sub> <i>n<\/i>, and Peres further conjectured that for any fixed <i>d<\/i> the simple random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) has cutoff <i>whp<\/i>.<\/p>\n<p>In this work we confirm the above conjectures, and establish cutoff in total-variation, its location and its optimal window, both for simple and for non-backtracking random walks on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>). Namely, for any fixed <i>d<\/i>, the <i>simple<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff at d\/(d-2) log<i><sub>d<\/sub><\/i><sub>-1<\/sub> <i>n<\/i> with window order sqrt{log <i>n<\/i>}. Surprisingly, the <i>non-backtracking<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff already at log<sub>d-1<\/sub> <i>n<\/i> with <i>constant<\/i> window order. We further extend these results to <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) for any <i>d<\/i>=<i>n<\/i><sup>o(1)<\/sup> (beyond which the mixing time is O(1)), provide efficient algorithms for testing cutoff, as well as give explicit constructions where cutoff occurs.<\/p>\n<p>Joint work with Allan Sly.<\/p>\n<\/blockquote>\n<p>3:00 <a href=\"http:\/\/www.math.washington.edu\/~soumik\/\"><b>Soumik Pal<\/b><\/a> (UW)<\/p>\n<blockquote>\n<p>Applications of a skew-product decomposition for the Bessel-Squared processes<\/p>\n<p><em>Abstract:<\/em> We consider different models arising in three distinct areas of probability: Watterson\u2019s Infinitely-Many-Neutral-Alleles model from mathematical biology, the Volatility-Stabilized-Market model of Fernholz and Karatzas in mathematical finance, and the embedding of large forests of critical Galton-Watson trees in Brownian motion. We show that all these models have a structure in which a skew-product decomposition of the Bessel-Squared processes play an important role. As a conclusion we see the emergence of a limiting Poisson-Dirichlet structure for each of them. For Watterson\u2019s model, this conclusion was proved earlier by Ethier and Kurtz via a different method. For the other models, these conclusions are new. In particular, we solve a problem posed by Fernholz and Karatzas with regards to the distribution of the \u2018market weights\u2019 functionals of the VSM model.<\/p>\n<\/blockquote>\n<p>3:45 <b>Tea<\/b><\/p>\n<p>4:15 <a href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\"><b>Edward Waymire<\/b><\/a> (OSU)<\/p>\n<blockquote>\n<p>Skew Brownian Motion and Applications in Fluid Dispersion<\/p>\n<p><em>Abstract:<\/em> Skew Brownian motion was introduced by Ito and Mckean in a classic 1963 paper devoted to constructions of various stochastic processes associated with Feller\u2019s classification of one-dimensional diffusions. Its basic properties and extensions have been the subject of a number of papers in the foundations of probability theory (many by probabilists in the Pacific Northwest !) In this talk we will discuss some recent and ongoing applications that arose out of discussions with colleagues in the geosciences at OSU. In particular this has led to the derivation of apparently new formulae for joint densities involving skew Brownian motion (with drift) and local and occupation times.<\/p>\n<p>It is based on joint work with OSU student and colleagues Thilanka Appuhamillage, Vrushali Bokil, Enrique Thomann, Brian Wood, and Jorge Ramirez (now at the University of Arizona).<\/p>\n<\/blockquote>\n<p>5:00 <b>Open problem solutions, conclude <\/b><\/p>\n<p>5:45 <b>Dinner<\/b> (not hosted)<\/p>\n<blockquote>\n<p><a href=\"http:\/\/mattsrotisserie.com\/\">Matts\u2019 Rotisserie and Oyster Lounge<\/a><\/p>\n<\/blockquote>\n<!-- \/wp:freeform -->\n<!-- \/wp:msr\/content-tab -->\n<!-- \/wp:msr\/content-tabs -->","tab-content":[{"id":0,"name":"Summary","content":"This is a recap of the\u00a0tenth Northwest Probability Seminar\u00a0was a one-day mini-conference organized by the <a href=\"http:\/\/www.math.washington.edu\/\">University of Washington<\/a>, the <a href=\"http:\/\/math.oregonstate.edu\/\">Oregon State University<\/a>, the <a href=\"http:\/\/www.math.ubc.ca\/\">University of British Columbia<\/a>, the <a href=\"http:\/\/math.uoregon.edu\/\">University of Oregon<\/a>, and the <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/group\/theory-group\/\">Theory Group<\/a> at <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\">Microsoft Research<\/a>. Usually the conference is hosted at the University of Washington, but this year the conference\u00a0was hosted at Microsoft.\r\n\r\nSupported by the <a href=\"http:\/\/www.msri.org\/\"><b>Mathematical Sciences Research Institute<\/b><\/a> (MSRI),\r\n<a href=\"https:\/\/www.microsoft.com\/en-us\/research\/\"><b>Microsoft Research<\/b><\/a>, and the <a href=\"http:\/\/pims.math.ca\/\"><b>Pacific Institute for the Mathematical Sciences<\/b><\/a> (PIMS).\r\n\r\nThe <a href=\"http:\/\/www.math.washington.edu\/~sheetz\/Obituaries\/zwbirnbaum.html\"><b>Birnbaum<\/b><\/a><b> Lecture in Probability<\/b> was given by <a href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><\/a> (Cornell). The other speakers were <a href=\"http:\/\/www.math.ubc.ca\/~angel\/\">Omer Angel<\/a> (UBC), Eyal Lubetzky (MSR), <a href=\"http:\/\/www.math.washington.edu\/~soumik\/\">Soumik Pal<\/a> (UW), and <a href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\">Edward Waymire<\/a> (OSU).\r\n\r\n[<a href=\"http:\/\/www.math.washington.edu\/~burdzy\/nwprob2008photos.php\">Speaker photographs<\/a>] [<a href=\"http:\/\/www.math.washington.edu\/~burdzy\/birnbaumspeakers.php\">Past Birnbaum speakers<\/a>]\r\n\r\nThe Scientific Committee for the 2008 NW Probability Seminar consisted of <a href=\"http:\/\/www.math.ubc.ca\/~barlow\/\">Martin Barlow<\/a> (U British Columbia), <a href=\"http:\/\/www.math.washington.edu\/~burdzy\/\">Chris Burdzy<\/a> (U Washington), <a href=\"http:\/\/www.math.washington.edu\/~zchen\/\">Zhen-Qing Chen<\/a> (U Washington), <a href=\"http:\/\/www.math.oregonstate.edu\/people\/view\/kovchegy\">Yevgeniy Kovchegov<\/a> (Oregon State U), <a href=\"http:\/\/darkwing.uoregon.edu\/~dlevin\/\">David Levin<\/a> (U Oregon), and <a href=\"https:\/\/www.microsoft.com\/en-us\/research\/people\/peres\/\">Yuval Peres<\/a> (Microsoft)."},{"id":1,"name":"Schedule","content":"9:30 <b>Coffee and muffins<\/b>\r\n\r\n10:30 <a href=\"http:\/\/www.math.cornell.edu\/People\/Faculty\/saloffcoste.html\"><b>Laurent Saloff-Coste<\/b><\/a> (Cornell)\r\n<blockquote>Behavior of Brownian motion on compact Lie groups as a function of dimension (e.g., on special orthogonal groups).\r\n\r\n<em>Abstract:<\/em> The distribution of Brownian motion on a compact manifold converge to its equilibrium (the normalized volume measure). Quantitatively, for natural families of compact manifolds, this convergence depends on certain geometric properties. In this talk we will focus on compact Lie groups such as the family of special orthogonal groups and consider the convergence of Brownian motion as the dimension grows to infinity.<\/blockquote>\r\n11:30 <a href=\"http:\/\/www.math.ubc.ca\/~angel\/\"><b>Omer Angel<\/b><\/a> (UBC)\r\n<blockquote>Colouring Voronoi\r\n\r\n<em>Abstract:<\/em> We consider the problem of colouring the planar map given by the Voronoi tessellation corresponding to a Poisson process in R^2. We seek colouring rules that are isometry invariant and are factors of the Poisson process. We prove that 6 colours suffice.<\/blockquote>\r\n<blockquote>Joint work with Itai Benjamini, Ori Gurel-Gurevich, Tom Meyerovitch, and Ron Peled.<\/blockquote>\r\n12:15 <b>Open problems and microtalks<\/b>\r\n\r\n1:00 <b>Lunch <\/b>(catered)\r\n\r\n2:15 <b>Eyal Lubetzky<\/b> (MSR)\r\n<blockquote>Cutoff phenomena for random walks on random regular graphs\r\n\r\n<em>Abstract:<\/em> The cutoff phenomenon describes a sharp transition in the convergence of a family of ergodic finite Markov chains to equilibrium. Many natural families of chains are conjectured to exhibit cutoff, yet establishing this fact is often extremely challenging. An important such family of chains is the random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>), a random <i>d<\/i>-regular graph on <i>n<\/i> vertices. Friedman determined the constant spectral gap of this class of chains for <i>d<\/i> fixed, implying a mixing-time of O(log <i>n)<\/i>. Durrett conjectured that the mixing time of the lazy random walk on a random 3-regular graph is <i>whp<\/i> (6+o(1))log<sub>2<\/sub> <i>n<\/i>, and Peres further conjectured that for any fixed <i>d<\/i> the simple random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) has cutoff <i>whp<\/i>.\r\n\r\nIn this work we confirm the above conjectures, and establish cutoff in total-variation, its location and its optimal window, both for simple and for non-backtracking random walks on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>). Namely, for any fixed <i>d<\/i>, the <i>simple<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff at d\/(d-2) log<i><sub>d<\/sub><\/i><sub>-1<\/sub> <i>n<\/i> with window order sqrt{log <i>n<\/i>}. Surprisingly, the <i>non-backtracking<\/i> random walk on <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) <i>whp<\/i> has cutoff already at log<sub>d-1<\/sub> <i>n<\/i> with <i>constant<\/i> window order. We further extend these results to <i>G<\/i>(<i>n<\/i>,<i>d<\/i>) for any <i>d<\/i>=<i>n<\/i><sup>o(1)<\/sup> (beyond which the mixing time is O(1)), provide efficient algorithms for testing cutoff, as well as give explicit constructions where cutoff occurs.\r\n\r\nJoint work with Allan Sly.<\/blockquote>\r\n3:00 <a href=\"http:\/\/www.math.washington.edu\/~soumik\/\"><b>Soumik Pal<\/b><\/a> (UW)\r\n<blockquote>Applications of a skew-product decomposition for the Bessel-Squared processes\r\n\r\n<em>Abstract:<\/em> We consider different models arising in three distinct areas of probability: Watterson's Infinitely-Many-Neutral-Alleles model from mathematical biology, the Volatility-Stabilized-Market model of Fernholz and Karatzas in mathematical finance, and the embedding of large forests of critical Galton-Watson trees in Brownian motion. We show that all these models have a structure in which a skew-product decomposition of the Bessel-Squared processes play an important role. As a conclusion we see the emergence of a limiting Poisson-Dirichlet structure for each of them. For Watterson's model, this conclusion was proved earlier by Ethier and Kurtz via a different method. For the other models, these conclusions are new. In particular, we solve a problem posed by Fernholz and Karatzas with regards to the distribution of the 'market weights' functionals of the VSM model.<\/blockquote>\r\n3:45 <b>Tea<\/b>\r\n\r\n4:15 <a href=\"http:\/\/www.math.oregonstate.edu\/~waymire\/\"><b>Edward Waymire<\/b><\/a> (OSU)\r\n<blockquote>Skew Brownian Motion and Applications in Fluid Dispersion\r\n\r\n<em>Abstract:<\/em> Skew Brownian motion was introduced by Ito and Mckean in a classic 1963 paper devoted to constructions of various stochastic processes associated with Feller's classification of one-dimensional diffusions. Its basic properties and extensions have been the subject of a number of papers in the foundations of probability theory (many by probabilists in the Pacific Northwest !) In this talk we will discuss some recent and ongoing applications that arose out of discussions with colleagues in the geosciences at OSU. In particular this has led to the derivation of apparently new formulae for joint densities involving skew Brownian motion (with drift) and local and occupation times.\r\n\r\nIt is based on joint work with OSU student and colleagues Thilanka Appuhamillage, Vrushali Bokil, Enrique Thomann, Brian Wood, and Jorge Ramirez (now at the University of Arizona).<\/blockquote>\r\n5:00 <b>Open problem solutions, conclude <\/b>\r\n\r\n5:45 <b>Dinner<\/b> (not hosted)\r\n<blockquote><a href=\"http:\/\/mattsrotisserie.com\/\">Matts' Rotisserie and Oyster Lounge<\/a><\/blockquote>"}],"msr_startdate":"2008-11-08","msr_enddate":"2008-11-08","msr_event_time":"","msr_location":"Redmond, WA","msr_event_link":"","msr_event_recording_link":"","msr_startdate_formatted":"November 8, 2008","msr_register_text":"Watch now","msr_cta_link":"","msr_cta_text":"","msr_cta_bi_name":"","featured_image_thumbnail":null,"event_excerpt":"This is a recap of the\u00a0tenth Northwest Probability Seminar\u00a0was a one-day mini-conference organized by the University of Washington, the Oregon State University, the University of British Columbia, the University of Oregon, and the Theory Group at Microsoft Research. Usually the conference is hosted at the University of Washington, but this year the conference\u00a0was hosted at Microsoft. Supported by the Mathematical Sciences Research Institute (MSRI), Microsoft Research, and the Pacific Institute for the Mathematical Sciences (PIMS).&hellip;","msr_research_lab":[199565],"related-researchers":[],"msr_impact_theme":[],"related-academic-programs":[],"related-groups":[],"related-projects":[],"related-opportunities":[],"related-publications":[],"related-videos":[],"related-posts":[],"_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event\/199649","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event"}],"about":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/types\/msr-event"}],"version-history":[{"count":2,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event\/199649\/revisions"}],"predecessor-version":[{"id":874269,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event\/199649\/revisions\/874269"}],"wp:attachment":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media?parent=199649"}],"wp:term":[{"taxonomy":"msr-research-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/research-area?post=199649"},{"taxonomy":"msr-region","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-region?post=199649"},{"taxonomy":"msr-event-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-event-type?post=199649"},{"taxonomy":"msr-video-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-video-type?post=199649"},{"taxonomy":"msr-locale","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-locale?post=199649"},{"taxonomy":"msr-program-audience","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-program-audience?post=199649"},{"taxonomy":"msr-post-option","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-post-option?post=199649"},{"taxonomy":"msr-impact-theme","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-impact-theme?post=199649"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}