{"id":777,"date":"2023-06-24T10:47:10","date_gmt":"2023-06-24T17:47:10","guid":{"rendered":"https:\/\/dornsife.usc.edu\/sergey-lototsky\/?page_id=777"},"modified":"2023-06-25T18:23:47","modified_gmt":"2023-06-26T01:23:47","slug":"math-606-summer-2021","status":"publish","type":"page","link":"https:\/\/dornsife.usc.edu\/sergey-lototsky\/math-606-summer-2021\/","title":{"rendered":"Math 606: Topics in Stochastic Processes, Summer 2021"},"content":{"rendered":"\n\n  \n    \n\n\n\n\n\n\n<div\n  class=\"cc--component-container cc--rich-text \"\n\n  \n  \n  \n  \n  \n  \n  >\n  <div class=\"c--component c--rich-text\"\n    \n      >\n\n    \n      \n<div class=\"f--field f--wysiwyg\">\n\n    \n  <h3 align=\"center\">Math 606, Summer 2021.<br \/>\nTopics in Stochastic Processes (054&#8211;39482R)<br \/>\nSingular Stochastic Ordinary Differential Equations<br \/>\n<span style=\"color: red;\"> Class meetings: MW, 9:30am-12:30pm, On line. <\/span><\/h3>\n<p>&nbsp;<\/p>\n<h4 align=\"center\">Information on this and related pages changes frequently.<\/h4>\n<h4><strong> Instructor: <\/strong> <a href=\"\/\"> Sergey Lototsky<\/a><br \/>\n<strong> Office:<\/strong> KAP 248D.<br \/>\n<strong> Phone:<\/strong> 213 740 2389<br \/>\n<strong> E-mail:<\/strong> lototsky usc edu.<\/h4>\n<p><strong> URL:\u00a0https:\/\/dornsife.usc.edu\/sergey-lototsky\/<\/strong><\/p>\n<p><strong>Office Hours:<\/strong> MW before and after the class. Appointments at other time are welcome.<\/p>\n<p><strong> Course objective <\/strong>To understand one-dimensional SODEs beyond the standard existence\/uniqueness theorem<\/p>\n<p><strong> Course work: <\/strong>Class participation, homework assignments, final presentation.<\/p>\n<p><strong> Official grading scheme: <\/strong>20% class participation, 40% homework assignments, 40% final presentation.<\/p>\n<p><strong> Main reference: <\/strong>Alexander S<strong>. <\/strong>Cherny and Hans-J\u00fcrgen Engelbert. <span class=\"title\">Singular stochastic differential equations. <\/span>Lecture Notes in Mathematics, 1858<a href=\"https:\/\/mathscinet-ams-org.libproxy2.usc.edu\/mathscinet\/search\/series.html?id=589\">.<\/a> <em>Springer-Verlag, Berlin,<\/em> 2005. viii+128 pp. ISBN: 3-540-24007-1. <em>The book is available in electronic form through the the USC Libraries, for example, by following the MathSciNet link.<\/em><\/p>\n<p><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/SingularSODEs.pdf\" target=\"_blank\" rel=\"noopener\"><strong>The main file<\/strong> <\/a>containing the homework problems and some ideas to remember; the file will be constantly updated as we proceed with the class.<\/p>\n<p><strong>Additional references:<\/strong><\/p>\n<ul>\n<li>O. Kallenberg, Foundations of Modern Probability (Springer, 1997), Chapters 19 amd 20.<\/li>\n<li>S. Karlin and H. M. Taylor, A Second Course in Stochastic Processes (Academic Press, 1981), Chapter 15.<\/li>\n<li>I. Karatzas and S. Shreve, Brownian Motion and Stochastic Calculus, Second Edition (Springer, 1991), Sections 3.6, 3.7, and 5.5.<\/li>\n<\/ul>\n<p><strong>My notes:<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/StochAnalysis.pdf\" target=\"_blank\" rel=\"noopener\">Stochastic analysis in continuous time <\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/BM-summary.pdf\" target=\"_blank\" rel=\"noopener\">A summary of Brownian motion<\/a><strong><br \/>\n<\/strong><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/SODEs-Summary.pdf\" target=\"_blank\" rel=\"noopener\">A summary of SODEs<\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/LocalTime-summary.pdf\" target=\"_blank\" rel=\"noopener\">A summary of local time<\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/MarkovProc.pdf\" target=\"_blank\" rel=\"noopener\">A summary of Markov processes<\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/MarkovProcErgodicity-Summary.pdf\" target=\"_blank\" rel=\"noopener\">A summary of ergodic theory<\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/CmMartGsvMeyerTheorem.pdf\" target=\"_blank\" rel=\"noopener\">A summary of the Girsanov theorem and related results<\/a><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/OneD-Diffusions.pdf\" target=\"_blank\" rel=\"noopener\">A summary of diffusions in one dimension<\/a><\/li>\n<\/ul>\n<p><strong>Other notes:<br \/>\n<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/Delbaen-Shirakawa.pdf\" target=\"_blank\" rel=\"noopener\">Delbaen and Shirakawa<\/a> on dX=B(X)dW<strong><br \/>\n<\/strong><\/li>\n<li><a href=\"https:\/\/dornsife.usc.edu\/sergey-lototsky\/wp-content\/uploads\/sites\/211\/2023\/06\/StrictLocalMartingale-1.png\" target=\"_blank\" rel=\"noopener\">A strict local martingale<\/a><\/li>\n<\/ul>\n<p><strong>Our progress:<\/strong><\/p>\n<p><span style=\"text-decoration: underline;\">May 19<\/span>: General introduction and examples of singular SODEs (interest rate models, Bessel processes, continuum versions of the Wright-Fisher model in biology)<\/p>\n<p><span style=\"text-decoration: underline;\">May 24<\/span>: Survey of stochastic analysis in continuous time; strong and weak solutions of SODEs.<\/p>\n<p><span style=\"text-decoration: underline;\">May 26<\/span>: What combinations of weak\/in distribution and strong\/pathwise are possible? Scale function and removal of drift. OU, GBM, and other affine equations. Bernoulli SODE and an example of local existence on a random time interval.<\/p>\n<p><span style=\"text-decoration: underline;\">May 3<\/span>1: Memorial Day; no class.<\/p>\n<p><span style=\"text-decoration: underline;\">June 2<\/span>: Constructing a non-zero solution of dX=X^{1\/3}dW, X(0)=0<\/p>\n<p><span style=\"text-decoration: underline;\">June 7<\/span>: A close look at dX=B(X(t))dW(t), B^2(x)&gt;0, x&gt;0.<\/p>\n<p><span style=\"text-decoration: underline;\">June 9<\/span>: The equation dX=B(X(t))dW(t) in general: the theorems of Engelbert and Schmidt.<\/p>\n<p><span style=\"text-decoration: underline;\">June 14<\/span>: One-dimensional diffusions: characterizations and the canonical form of the generator<\/p>\n<p><span style=\"text-decoration: underline;\">June 16<\/span>: Boundary points, boundary conditions, and Feller&#8217;s criteria for (non)explosion<\/p>\n<p><span style=\"text-decoration: underline;\">June 21<\/span>: Ergodicity and Khasminskii&#8217;s criteria\u00a0 for (non)explosion.<\/p>\n<p><span style=\"text-decoration: underline;\">June 23<\/span>: Comparative analysis of Feller&#8217;s and Khasminskii&#8217;s criteria for (non)explosion.<\/p>\n<p><span style=\"text-decoration: underline;\">June 28<\/span>: KL expansion and related topics; a summary of strong solutions.<\/p>\n<p><span style=\"text-decoration: underline;\">June 30<\/span>: A (problem-solving) discussion.<\/p>\n\n\n\n<\/div>\n\n\n  <\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":282,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-777","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.1.1 - 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