Ical
https://mathematics.huji.ac.il/calendar?type=month&month=term
en<a href="https://mathematics.huji.ac.il/event/amitsur-memorial-symposium?delta=0" >Amitsur Memorial Symposium 2018</a>
https://mathematics.huji.ac.il/event/amitsur-memorial-symposium
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<img height="160" width="110" style="width: 110px; height: 160px; margin: 10px; float: left;" class="media-element file-default file-os-files-small" src="https://mathematics.huji.ac.il/sites/default/files/styles/os_files_small/public/mathen/files/amitsur87_small.jpg?m=1510230719&itok=GpAwsVcl" alt="" title="" />The <em>Amitsur Memorial Symposium</em> is an annual conference in memory of Prof. Shimshon Avraham Amitsur. It is hosted by a different institution each year.
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The 25th <em>Amitsur Memorial Symposium </em>will be held at the Einstein Institute of Mathematics, the Hebrew University of Jerusalem.
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<!--break-->Speakers, titles and abstracts
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<strong>Yael Algom-Kfir</strong><br />Title:<b> </b><strong>The completion of a non-symmetric metric space</strong>
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<strong>Amiram Braun</strong><br />Title: <strong>The polynomial question in modular invariant theory, old and new</strong>.<br />Abstract: 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.
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<strong>Tsachik Gelander</strong><br />Title: <strong>Local rigidity of uniform lattices</strong><br />Abstract. 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.<br />This is a joint work with Arie Levit.
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<strong>Lev Glebsky</strong><br />Title: <strong>Approximations of groups by finite and linear groups</strong>.<br />Abstract: The sofic groups and hyperlinear groups are groups approximable by finite symmetric<br />and by unitary groups, respectively. I recall their definitions and discuss why those classes of groups<br />are interesting. Then I consider approximations by other classes of groups and review some results,<br />including rather recent ones by N. Nikolov, J. Schneider, A.Thom, <a href="https://arxiv.org/abs/1703.06092" target="_blank" title="">https://arxiv.org/abs/1703.06092</a> .<br />If time permits I'll speak about stability and its relations with approximability.
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<strong>Arye Juhasz</strong><br />Title: <strong>On the center of Artin groups</strong>.<br />Abstract: Let A be an Artin group. It is known that if A is spherical (of finite type) and irreducible (not a direct sum), then it has infinite cyclic center.<br />It is conjectured that all other irreducible Artin groups have trivial center. I prove this conjecture under a stronger assumption that not being spherical namely, if there is a standard generator which is not contained in any 3-generated spherical standard parabolic subgroup. The main tool is relative presentations of Artin groups.
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<strong>Alex Lubotzky</strong><br /> Title: <strong> First order rigidity of high-rank arithmetic groups</strong><br /> Abstract: The family of high rank arithmetic groups is a class of groups playing an important role in various areas of mathematics. <br /> It includes SL(n,Z), for n>2 , SL(n, Z[1/p] ) for n>1, their finite index subgroups and many more. <br />A number of remarkable results about them have been proven including; Mostow rigidity, Margulis Super rigidity and the Quasi-isometric rigidity. <br />We will talk about a new type of rigidity : "first order rigidity". Namely if G is such a non-uniform characteristic zero arithmetic group and H a finitely generated group which is elementary equivalent to it then H is isomorphic to G. <br />This stands in contrast with Zlil Sela's seminal work which implies that the free groups, surface groups and hyperbolic groups (many of which are low-rank arithmetic groups) have many non isomorphic finitely generated groups which are elementary equivalent to them.<br />Joint work with Nir Avni and Chen Meiri.
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<strong>Chloe Perin</strong><br />Title: <strong>Forking independence in the free group</strong><br />Abstract: 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.
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<strong>Elyiahu Rips</strong><br />Title: <strong>Free Engel groups</strong><br />Abstract: A free n-Engel group is the relatively free group of the variety of groups with the identical relation [x, y, y,...,y (n times)]=1. Let n>=20. We show that the free Engel group on at least two generators is not locally nilpotent. Our approach to Engel groups combines<br />geometric and combinatorial methods. On the geometric side, we consider graded van Kampen diagrams, and we prove that they display (discrete) negative curvature properties. To do this, we construct a canonical form of elements in each consecutive rank (this is the combinatorial aspect). Using the canonical form, we obtain "parallel meetings" between the regions of higher ranks of the graded van Kampen diagram and, using surgery, improve it to direct meeting. The combinatorial structure of the relators secures that this direct meeting is (relatively) short. Given the structure of graded van Kampen diagrams, we deduce a graded version of Greendlinger's Lemma and then establish the properties of the group.<br />Joint work with Arye Juhasz
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<strong>Malka Schaps</strong><br />Title: <strong>Symmetric Kashivara crystals of type A in low rank</strong><br />Abstract: The basis of elements of the highest weight representations of affine Lie algebra of type A can be labeled in three different ways, my multipartitions, by piecewise linear paths in the weight space, and by canonical basis elements. The entire infinite basis is recursively generated from the highest weight vector of operators f_i from the Chevalley basis of the affine Lie algebra, and organized into a crystal called a Kashiwara crystal. We describe cases where one can move between the different labelings in a non-recursive fashion, particularly when the crystal has some symmetry.<br />Joint work with Ola Amara-Omari
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<strong>Aner Shalev</strong><br />Title: <strong>The length and depth of finite groups, algebraic groups and Lie groups</strong><br />Abstract: The length of a finite group G is defined to be the maximal length of an unrefinable chain of subgroups going from G to 1. This notion was studied by many authors since the 1940s.<br />Recently there is growing interest also in the depth of G, which is the minimal length of such a chain. Moreover, similar notions were defined and studied for important families of infinite groups, such as connected algebraic groups and connected Lie groups.<br />I will describe recent works on these topics, joint with Tim Burness and Martin Liebeck. The proofs use<br />a variety of tools, including recent results in analytic number theory.
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Programme
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<br /><strong>Tuesday, June 26th</strong>:
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9:30 -- Gathering
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10:00 -- Lubotzky
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11:00 -- Coffee break
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11:30 -- Schaps
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12:30 -- Lunch break
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14:00 -- Juhasz
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15:00 -- Shalev
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16:00 -- Coffee break
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16:30 -- Glebsky
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The symposium dinner will be held in the evening, the exact time and location will be announced later.<br />The dinner will be attended by Amitsur's children.
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<strong>Wednesday, June 27th</strong>:
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10:00 -- Rips
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11:00 -- Coffee break
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11:30 -- Braun
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12:30 -- Lunch break
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14:00 -- Perin
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15:00 -- Gelander
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16:00 -- Coffee break
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16:30 -- Algom-Kfir.
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Mon, 25 Jun 2018 21:00:00 +0000naavahl57072 at https://mathematics.huji.ac.il<a href="https://mathematics.huji.ac.il/event/groups-geometry-and-representations-mathematical-institute-oxford-celebrating-dan-segal?delta=0" >Groups, Geometry and Representations @ Oxford: Celebrating Dan Segal and Aner Shalev </a>
https://mathematics.huji.ac.il/event/groups-geometry-and-representations-mathematical-institute-oxford-celebrating-dan-segal
<!--break--><img height="1000" width="707" alt="aner-60" class="media-element file-default file-os-files-xxlarge" src="https://mathematics.huji.ac.il/sites/default/files/styles/os_files_xxlarge/public/mathen/files/aner-conferences.jpg?m=1518502443&itok=wU0KJdVk" title="" /><p>
<a href="https://sites.google.com/view/ggroxford2018/home" title="">More information here.</a>
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Sun, 02 Sep 2018 21:00:00 +0000tamarz52625 at https://mathematics.huji.ac.il<a href="https://mathematics.huji.ac.il/event/einstein-institute-international-undergraduate-workshop?delta=0" >The Einstein Institute International Undergraduate Workshop </a>
https://mathematics.huji.ac.il/event/einstein-institute-international-undergraduate-workshop
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<!--break-->(with support from École Polytechnique and Freie Universität Berlin)
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October 2nd - 11th 2018
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Description
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The Einstein Institute of Mathematics will host a 10 day undergraduate workshop, bringing together outstanding (2nd and 3rd year) undergraduate students from Israel and abroad.<br />The workshop will be centered around two seminar-style courses, each one consisting of talks given by the students themselves and moderated by a faculty member from the institute.<br />This year the topics are:
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<u>Topics in the Theory of Zeta and L-Functions </u> (moderated by <b>Jasmin Matz</b>).
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Description: The Riemann zeta function is the prototypical example of a large zoo of ζ- and L-function. Such functions are of central interests in modern number theory. In this seminar we are going to study several examples with an emphasis on analytical and spectral aspects.
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<u>Polytopes </u> (moderated by <b>Eran Nevo</b>).
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Description: Polytopes have fascinated humans since antiquity and are related to many areas of modern mathematics. We will study polytopes, focusing on connections between their geometric and combinatorial properties.
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</ul><br />In addition, there will be minicourses by <b>Klaus Altmann</b> (FU Berlin) and <b>Jake Solomon</b> (HUJI), guest lectures, and a social program.<br />More information regarding the program will be posted <a href="http://www.math.huji.ac.il/~workshop" title="">here</a>, as it becomes available.<br />Check out the workshop's posters in <a href="/mathen/files/undergrad_workshop_2018_poster_english.pdf" title="">English</a> and <a href="/mathen/files/undergrad_workshop_2018_poster_hebrew.pdf" title="">Hebrew</a>!
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Location and Dates
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The workshop will take place at <a href="http://www.mathematics.huji.ac.il"> the Einstein Institute of Mathematics </a>, <a href="http://www.huji.ac.il"> the Hebrew University of Jerusalem </a>, Jerusalem, Israel.<br />Participants are expected to arrive the day before, on Sunday, October 1st, and the workshop will end on Thursday, October 11th in the afternoon.
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Applications
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To apply please send an email to <a href="mailto:huji.math.undergrad.workshop@gmail.com">huji.math.undergrad.workshop@gmail.com </a> with the following information:
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Your name, gender, address, and institution.
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A grade transcript with a clear listing of the courses you've taken so far in your mathematical studies (an informal transcript is OK).
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The name of a contact person from whom we may request a recommendation letter if needed.
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</ul><br />An application with only partial information (for example, if you don't have a contact person who'll write you a letter), is better than no application at all!<br />Applications received by Friday, June 15th, 2018, will receive full consideration.
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Financial Support, Lodging, Etc.
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Partial support towards travel is available.<br />Shared lodging (two in a room) at the <a href="http://bretter.huji.ac.il/"> Bretter House,</a> as well as breakfast and lunch will be provided for accepted participants.<br />For inquiries please email <a href="mailto:huji.math.undergrad.workshop@gmail.com">huji.math.undergrad.workshop@gmail.com </a>
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</ul>Mon, 01 Oct 2018 21:00:00 +0000tamarz53898 at https://mathematics.huji.ac.il<a href="https://mathematics.huji.ac.il/event/random-walks-groups-and-stationary-random-graphs?delta=0" >Random Walks on Groups and Stationary Random Graphs</a>
https://mathematics.huji.ac.il/event/random-walks-groups-and-stationary-random-graphs
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In this workshop we intend to explore which methods and results can be extended from the realm of groups to stationary random graphs. In doing so we hope to gain better understanding of the factors that determine each random walk behavior, both on stationary random graphs and on Cayley graphs.
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<a href="http://ias.huji.ac.il/RandomWalks" target="_blank" title="">More information</a>
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Sat, 06 Oct 2018 21:00:00 +0000naavahl57071 at https://mathematics.huji.ac.il