Events & Seminars

  • 2018 Jun 28

    Basic Notions: Barry Simon "More Tales of our Forefathers (Part II)"

    4:00pm to 5:30pm

    Location: 

    Manchester Hall 2
    This is not a mathematics talk but it is a talk for mathematicians. Too often, we think of historical mathematicians as only names assigned to theorems. With vignettes and anecdotes, I'll convince you they were also human beings and that, as the Chinese say, "May you live in interesting times" really is a curse. Among the mathematicians with vignettes are Riemann, Newton, Poincare, von Neumann, Kato, Loewner, Krein and Noether.
  • 2018 Jun 28

    Colloquium: Barry Simon (Caltech) - "More Tales of our Forefathers"

    2:30pm to 3:30pm

    Location: 

    Manchester Building (Hall 2), Hebrew University Jerusalem
    This is not a mathematics talk but it is a talk for mathematicians. Too often, we think of historical mathematicians as only names assigned to theorems. With vignettes and anecdotes, I'll convince you they were also human beings and that, as the Chinese say, "May you live in interesting times" really is a curse. Among the mathematicians with vignettes are Riemann, Newton, Poincare, von Neumann, Kato, Loewner, Krein and Noether. This talk is in two parts. The second part will be given from 4:00 to 5:00 (not 5:30) in the Basic Notions seminar.
  • 2018 Jun 27

    Amitsur Symposium: Yael Algom-Kfir - "The metric completion of an asymmetric metric space"

    4:30pm to 5:30pm

    Location: 

    Manchester House, Lecture Hall 2
    The Teichmuller space with the Thurston metric and Outer Space with the Lipschitz metric are two examples of spaces with an asymmetric metric i.e. d(x,y) eq d(y,x). The latter case is also incomplete: There exist Cauchy sequences that do not have a limit. We develop the theory of the completion of an asymmetric space and give lots of examples. Time permitting we will describe the case of Outer Space.
  • 2018 Jun 27

    Amitsur Symposium: Tsachik Gelander - "Local rigidity of uniform lattices"

    3:00pm to 4:00pm

    Location: 

    Manchester House, Lecture Hall 2
    We establish topological local rigidity for uniform lattices in compactly generated groups, extending the result of Weil from the realm of Lie groups. We generalize the classical local rigidity theorem of Selberg, Calabi and Weil to irreducible uniform lattices in Isom(X) where X is a proper CAT(0) space with no Euclidian factors, not isometric to the hyperbolic plane. We deduce an analog of Wang’s finiteness theorem for certain non-positively curved metric spaces. This is a joint work with Arie Levit.
  • 2018 Jun 27

    Amitsur Symposium: Chloe Perin - "Forking independence in the free group"

    2:00pm to 3:00pm

    Location: 

    Manchester House, Lecture Hall 2
    Model theorists define, in structures whose first-order theory is "stable" (i.e. suitably nice), a notion of independence between elements. This notion coincides for example with linear independence when the structure considered is a vector space, and with algebraic independence when it is an algebraically closed field. Sela showed that the theory of the free group is stable. In a joint work with Rizos Sklinos, we give an interpretation of this model theoretic notion of independence in the free group using Grushko and JSJ decompositions.
  • 2018 Jun 27

    Analysis Seminar: Barry Simon (Caltech) "Heinävarra’s Proof of the Dobsch–Donoghue Theorem"

    12:00pm to 1:00pm

    Location: 

    Ross Building, Room 70
    Abstract: In 1934, Loewner proved a remarkable and deep theorem about matrix monotone functions. Recently, the young Finnish mathematician, Otte Heinävarra settled a 10 year old conjecture and found a 2 page proof of a theorem in Loewner theory whose only prior proof was 35 pages. I will describe his proof and use that as an excuse to discuss matrix monotone and matrix convex functions including, if time allows, my own recent proof of Loewner’s original theorem.
  • 2018 Jun 27

    Amitsur Symposium: Amiram Braun - "The polynomial question in modular invariant theory, old and new"

    11:30am to 12:30pm

    Location: 

    Manchester House, Lecture Hall 2
    Let G be a finite group, V a finite dimensional G- module over a field F, and S(V) the symmetric algebra of V. The above problem seeks to determine when is the ring of invariants S(V)^G , a polynomial ring. In the non-modular case (i.e. char(F) being prime to order(G)), this was settled in the Shephard-Todd-Chevalley theorem. The modular case (i.e. char(F) divides order (G) ), is still wide open. I shall discuss some older results due to Serre, Nakajima , Kemper-Malle and explain some new results, mostly in dimension 3.
  • 2018 Jun 27

    Logic Seminar - Shahar Oriel - "Erdos-Hajnal property for stable graphs"

    11:00am to 1:00pm

    Location: 

    Ross 63
    We will follow a short note by Artem Chernikov & Sergei Starchenko: "A note on the Erdos-Hajnal Conjecture." “In this short note we provide a relatively simple proof of the Erd ̋os–Hajnal conjecture for families of finite (hyper-)graphs without the m-order property. It was originally proved by M. Malliaris and S. Shelah”

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