האירועים הבאים

  • Cohn's theory of universal skew fields of fractions Feb 6, 11:30-Feb 18, 11:30, 2018, Room -101.

    Jurij Volcic (BGU) will give three lectures on the theory of universal skew fields of fractions due to P.M. Cohn, a beautiful and powerful tool of noncommutative algebra little known outside of a small circle of cognoscenti. Everybody is invited (the lectures should be accessible for graduate students).

    Time and place:

    Tuesday Feb. 6, Thursday Feb. 15, and Sunday Feb. 18 at 11:30-13:00 in Room -101

    Abstract:

    As opposed to the commutative setting, localization in noncommutative rings is a much more intricate topic, accompanied with various subtle obstacles and at first sight counter-intuitive phenomena. An exceptional contribution to this field has been made by Paul Moritz Cohn (1924-2006) with the introduction of universal skew fields of fractions in the 70’s, and his subsequent development of this theory. In the self-contained course of three talks I will try to present some of Cohn’s core results with the view towards the universal skew field of fractions of a free algebra.

    In the first lecture we will consider the general problem of embedding rings into skew fields, and early difficulties accompanying it. Following Cohn we will then introduce the category of epic skew fields and specializations assigned to a fixed ring. This will allow us to talk about universal skew fields of fractions and to draw parallels with the commutative theory.

    In the second lecture we will explain the interplay between specializations, singular kernels, matrix ideals in matrix representation of fractions. Our aim will be to determine necessary and sufficient conditions for a ring to admit a (universal) skew field of fractions.

    In the last lecture we will finally look at a concrete family of rings admitting universal skew fields of fractions: free ideal rings (firs), among which are free algebras, and their generalizations. We will trace down their distinguishing property that fulfills the sufficient condition from the previous lecture.

  • The Batsheva de Rothschild Seminar on Quasicrystals, Delone sets and Generalizations of Lattices(*) Mar 11, 16:43-Mar 16, 16:43, 2018, Sea of Galilee, at Ohalo Manor Hotel.

  • Set Theory, Model Theory and Applications(*) Apr 22-26, 2018, Eilat Campus of Ben-Gurion University of the Negev (Israel). Poster_2018.pdf

  • Noriko Sakurai award(*) May 8, 14:00-16:00, 2018.

האירועים האחרונים

  • Second Local Model Theory Day Dec 17, 11:00-17:00, 2017, Math -101.

  • A night of mathematics and Jazz(*) Nov 26, 18:00-22:00, 2017, Math -101. Haruka-and-Ehud.jpg

    All faculty and students are cordially invited.

    Program

    18:00 Undergraduate math club

    Barak Weiss, Tel Aviv University

    The illumination problem

    The following elementary problem in geometry is still open: given a polygon in the plane, say that points and in see each other if there is a billiard path from to . Is there a polygon in which infinitely many pairs of points do not see each other?

    Such problems turn out to be easy to state but very difficult to solve. I will explain this and related questions in greater detail, and describe some recent progress which relies on well-known work of Eskin and Mirzakhani (part of the late Maryam Mirzakhani’s Field medal citation).

    19:00 A Jazz show by Tsachik and the perverse sheaves

    Ehud Ettun on bass

    Haruka Yabuno on Piano

    Tsachik Gelander on drums

Some older events may be found on the pages of the Center for Advanced Studies.

אירועי העבר

(Star) מסמל אירועים הנתמכים בחלקם על-ידי המרכז ללימודים מתקדמים במתמטיקה באוניברסיטת בן-גוריון