Speaker: Xinyu Fang (Harvard)Title: A tour of the Betti, etale, de Rham, and crystalline cohomologyAbstract:This talk is a crash course on the properties of various cohomology theories that will be used in the Lawrence-Venkatesh proof. These include the Betti cohomology, etale cohomology, de Rham cohomology and crystalline cohomology. We review relevant structures on each of these cohomology groups of a smooth proper variety, state some comparison theorems, and explain how they come together to form the "big diagram" in the Lawrence-Venkatesh argument.Reference:$\bullet$ Poonen, $p$-adic approaches to rational and integral points on curves, Sections 5 and 6.For more details:$\bullet$ Deligne, Hodge cycles on abelian varieties, Section 1.$\bullet$ Lawrence and Venkatesh, Diophantine problems and $p$-adic period mappings, Section 3 (to see how cohomology theories are going to be used).$\bullet$ Brinon and Conrad, CMI summer school notes on $p$-adic Hodge theory, Section 9.1 (for details on the ring $B_{cris}$ and the functor $D_{cris}$).$\bullet$ Nicole, Cris is for Crystalline (notes for a seminar talk on crystalline cohomology) (for the definition and motivations for crystalline cohomology).$\bullet$ Voisin, Hodge theory and complex algebraic geometry I, Chapter II (for de Rham cohomology and the Hodge decomposition).

The MIT wrestling club holds practices in the du Pont Wrestling Room on weeknights 5:30-7pm. All levels of experience welcome! Whether you're looking to learn how to grapple or just want to get in a good workout, wrestling practice is a good time to learn technique, get in some live goes, and have fun with a great group of people.Current schedule is: structured practice MTRF, open mats W, and technique sessions 9-10:30am on Saturday. For more information, contact wrestling-officers@mit.edu.

Join us for a night of humor, media literacy, and creative deception at our February After Dark. In a twist on "Two Truths and a Lie," three comedians challenge your gullible gauge to spot the one true news story.Take inspiration from historical spirit photography to create your own deceptive imagery. Learn how Victorian photographers faked ghostly images, then try your hand at crafting your own illusions.MIT's Rand Lab will showcase interactive tools to help you spot fake news in real-time.Drinks from Marzae Wine and Philippine snacks from Lola's Pinoy Pastry will be available for purchase.Come for fun, stay for creativity, and leave with a sharper eye for truth in today's media.This event is co-hosted with MIT's Knight Science Journalism Program.

Writing Together Online offers structured time to help you spring into writing and stay focused this semester. We offer writing sessions every workday, Monday through Friday. Join our daily 90-minute writing sessions and become part of a community of scholars who connect online, set realistic goals, and write together in the spirit of accountability and camaraderie. The program is open to all MIT students, postdocs, faculty, staff, and affiliates who are working on papers, proposals, thesis/dissertation chapters, application materials, and other writing projects. For more information and to register, go to this link or check the WCC website. Please spread the word and join with colleagues and friends.Register for Spring 2025 Writing Challenge 1Choose those sessions that you want to attend during Challenge 1: February 10th through March 21stMondays 9:00–10:30amTuesdays 8–9:30am and 9:30–11amWednesdays 9:00–10:30amThursdays 8–9:30am and 9:30–11amFridays 8–9:30am and 9:30–11amMIT Students and postdocs who attend at least 5 sessions per challenge will be entered into a raffle of three $25 Amazon gift cards. The raffle will take place on Friday, March 21st. The more you participate, the more times you will be entered into the raffle of prizes.For more information and to register, check the WCC website. Please spread the word and join with peers and friends.The funding support for this program comes from the Office of Graduate Education

Writing Together Online offers structured time to help you spring into writing and stay focused this semester. We offer writing sessions every workday, Monday through Friday. Join our daily 90-minute writing sessions and become part of a community of scholars who connect online, set realistic goals, and write together in the spirit of accountability and camaraderie. The program is open to all MIT students, postdocs, faculty, staff, and affiliates who are working on papers, proposals, thesis/dissertation chapters, application materials, and other writing projects. For more information and to register, go to this link or check the WCC website. Please spread the word and join with colleagues and friends.Register for Spring 2025 Writing Challenge 1Choose those sessions that you want to attend during Challenge 1: February 10th through March 21stMondays 9:00–10:30amTuesdays 8–9:30am and 9:30–11amWednesdays 9:00–10:30amThursdays 8–9:30am and 9:30–11amFridays 8–9:30am and 9:30–11amMIT Students and postdocs who attend at least 5 sessions per challenge will be entered into a raffle of three $25 Amazon gift cards. The raffle will take place on Friday, March 21st. The more you participate, the more times you will be entered into the raffle of prizes.For more information and to register, check the WCC website. Please spread the word and join with peers and friends.The funding support for this program comes from the Office of Graduate Education

Chemistry Student Seminar (CSS) is a student-organized seminar series that host graduate students and postdocs to share their research in a friendly and informal environment. Free donuts and coffee are provided.