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--- seminars:template [2026/08/05 21:53] – created - external edit 127.0.0.1
+++ seminars:template [2026/08/07 13:24] (current) – jlasseter
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-=====Geometry and Topology Seminar=====
+=====Seminar Template=====
-We meet **Thursdays** at **2:45--3:45 pm** in **Whitney Hall 100E**. This semester's organizers are James Hyde and Lorenzo Ruffoni. The seminar has an announcement [[https://groups.google.com/a/binghamton.edu/g/topsem|mailing list]] open to all.
+This is a template for future seminar page construction.
-Topics include: geometric group theory, differential geometry and topology, low-dimensional topology, algebraic topology, and homotopy theory.
+A general description of the seminar, its goals, format, meeting time, etc. could go here
 -----
-=====Fall 2026=====
+==== Fall 2025 ====
-  * **8/20/2026** \\ Speaker: ** Yu-Chan Chang (Ohio State) ** \\ Title: **TBA** <WRAP box>// Abstract: //
-TBA\\ </WRAP>
+**Thursday Nov 6 4:00-5:00pm, WH-100E**\\  //Speaker//: ** [[ https://blogs.baruch.cuny.edu/aobus/ | Andrew Obus]] ** (CUNY) \\ //Topic//: **//The lifting problem for covers of curves, particularly its group-theoretical aspects//** \\
+<WRAP box 90%>
+**//Abstract//**:
+Whenever a mathematical object is given in
+characteristic p, one can ask whether it is the reduction, in some
+sense, of an analogous structure in characteristic zero.  If so, the
+structure in characteristic zero is called a "lift" of the structure
+in characteristic p.  The most famous example is Hensel's Lemma about
+lifting solutions of polynomials in Z/p to solutions in the p-adic
+integers Z_p.
+The “lifting problem” we consider is more geometric: given a smooth curve X in
+characteristic p with an action of a finite group G, is there a curve
+in characteristic zero with G-action that reduces to X?  Unsurprisingly, the answer is related to the group theory of G (for instance, if p does not divide |G| or if G is cyclic, then the curve with the G-action always lifts, but if G has an abelian, non-cyclic, non-p-subgroup that fixes a point on X, then the curve does not lift with the action).  After giving an introduction to the lifting problem and some examples, we will discuss well-established ways that the problem interacts with group theory, as well as more recent advances relating the problem to representation theory.\\
+</WRAP>
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 =====Past Semesters=====
-[[seminars:topsem:topsem_spring2026|Spring 2026]] | [[seminars:topsem:topsem_fall2025|Fall 2025]] | [[seminars:topsem:topsem_spring2025|Spring 2025]] | [[seminars:topsem:topsem_fall2024|Fall 2024]] | [[seminars:topsem:topsem_spring2024|Spring 2024]] | [[seminars:topsem:topsem_fall2023|Fall 2023]] | [[seminars:topsem:topsem_spring2023|Spring 2023]] | [[seminars:topsem:topsem_fall2022|Fall 2022]] | [[seminars:topsem:topsem_spring2022|Spring 2022]] | [[seminars:topsem:topsem_fall2021|Fall 2021]] | [[seminars:topsem:topsem_spring2021|Spring 2021]] | [[seminars:topsem:topsem_fall2020|Fall 2020]] | [[seminars:topsem:topsem_spring2020|Spring 2020]] | [[seminars:topsem:topsem_fall2019|Fall 2019]] | [[seminars:topsem:topsem_spring2019|Spring 2019]] | [[seminars:topsem:topsem_fall2018|Fall 2018]] | [[seminars:topsem:topsem_spring2018|Spring 2018]] | [[seminars:topsem:topsem_fall2017|Fall 2017]] | [[seminars:topsem:topsem_spring2017|Spring 2017]] | [[seminars:topsem:topsem_f16|Fall 2016]] | [[seminars:topsem:topsem_s16|Spring-Summer 2016]] | [[seminars:topsem:topsem_f15|Fall 2015]] | [[seminars:topsem:topsem_s15|Spring 2015]] | [[seminars:topsem:topsem_f14|Fall 2014]]
+(a list of past versions with links goes here)