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School HomeResearchPast Seminar informationPure Mathematics

# Past Pure Mathematics Seminars by Reverse Date

 Pure Mathematics Seminars (Historical) Spectacle cycles and modular forms Dr Jens Funke (Durham university) 27 May 2010 Harrison 203 Thursday 3pm Pure Mathematics The classical Shintani lift is the adjoint of the Shimura correspondence. It realizes periods of even weight cusp forms as Fourier coefficients of a half-integral modular form. In this talk we revisit the Shintani lift from a (co)homological perspective. In particular, we extend the lift to Eisenstein series and give a geometric interpretation of this extension. This is joint work with John Millson. TBA Professor Frances Kirwan (University Oxford) 18 Mar 2010 Harrison 106 Thursday 3pm Pure Mathematics irreducible $\Qp$-representations of compact $p$-adic analytic groups Dr Konstantin Ardakov (Nottingham university) 11 Mar 2010 Harrison 106 Thursday 3pm Pure Mathematics P-adic interpolation of automorphic forms Dr David Loeffler (University Warwick) 4 Mar 2010 Harrison 106 Thursday 3pm Pure Mathematics Coleman’s work on overconvergent p-adic modular forms shows that finite slope modular eigenforms can be interpolated p-adically, forming rigid-analytic families of eigenforms parametrised by their weights. This has been generalised by Emerton to cohomological automor- phic representations of a wide range of reductive groups, where the local factor at p is principal series. I shall give an exposition of Emerton’s construction, and of recent joint work with Richard Hill and myself in which we have extended this to certain non-principal-series cases p-adic L-functions of modular forms at supersingular primes Dr Antonio Lei (Cambridge university) 22 Feb 2010 Harrison 171 Monday 2pm Pure Mathematics On volumes of arithmetic hyperbolic n-orbifolds. Dr Mikhail Belolipetsky (Durham University) 15 Feb 2010 Harrison 106 Monday 2pm Pure Mathematics The main topic of my talk is the search for the minimal volume quotients of the hyperbolic n-space. In dimension 2 the problem was solved by Siegel who also asked about the general case. Since then a considerable progress has been made for the so-called arithmetic quotients and the only case which was still open is when the dimension n is odd and >3. After a brief introduction I will focus on the solution to this problem which we obtained in a recent joint work with Vincent Emery. Weiestrass Points and Automorphisms of Curves Dr Kay Magaard (University of Birmingham) 11 Feb 2010 Harrison 106 Thursday 3pm Pure Mathematics Let $X$ be a compact connected Riemann surface of genus $g \geq 2$. A point of $p \in X$ is Weierstrass if there exists a non-constant meromorphic function on $X$ that has a pole of order $\leq g$ at $p$ and is holomorphic on $X \setminus p$. A lemma of Sch\"oneberg asserts that if an automorphism $\alpha$ of $X$ fixes five or more points of $X$, then every one of them is a Weierstrass point. In the talk we will discuss the impact of Sch\"oneberg's lemma has on the structure of the automorphism group of $X$. Non-residually finite extension of arithmetic groups. Dr Richard Hill (University College London) 8 Feb 2010 Harrison 106 Monday 2pm Pure Mathematics Let Gamma be an arithmetic group with the congruence subgroup property, and with an associated Shimura variety. A theorem of Deligne states that there is a central extension of Gamma by a cyclic group which is not residually finite. This result was used by Toledo to give examples of complex projective varieties for which the topological fundamental group does not embed in the algebraic fundamental group. In the talk I'll generalize Deligne's result to the case that Gamma has no associated Shimura variety, so for example my result holds for congruence subgroups of SL(n,Z) with n at least 3. Congruences in noncommutative Iwasawa theory Dr Mahesh Kakde (University College London) 28 Jan 2010 Harrison 106 Thursday 3pm Pure Mathematics L-functions and Arithmetic Professor John Coates (Cambridge university) 14 May 2009 Harrison 101 Thursday 3pm Pure Mathematics The higher Hilbert symbol via (phi,G)-modules Dr Sarah Zerbes (Exeter university) 7 May 2009 Harrison 101 Thursday 3pm Pure Mathematics Parity of the rank of an elliptic curve: results Dr Tim Dokchitser (Cambridge university) 30 Apr 2009 Harrison 101 Thursday 4pm Pure Mathematics Parity of the rank of an elliptic curve: phenomena Dr Valadimir Dokchitser (Cambridge university) 30 Apr 2009 Harrison 101 Thursday 3pm Pure Mathematics Sha and Degree 4 del Pezzo Surfaces. Prof. Victor Flynn (Oxford University) 20 Mar 2009 Harrison LT04 Friday 2pm Pure Mathematics Skew Power Series Rings Prof. Otmar Venjakob (Heidelberg University) 19 Mar 2009 Harrison 101 Thursday 3pm Pure Mathematics Period Domains Modular Forms and Lattices Dr Gregory Sankaran (Bath University) 5 Mar 2009 Harrison 101 Thursday 3pm Pure Mathematics Manin-Mumford and Andre-Oort conjectures : a unified approach. Dr Andrei Yafaev (UCL) 19 Feb 2009 Harrison 101 Thursday 3pm Pure Mathematics Manin-Mumford and Andre-Oort conjectures : a unified approach. Dr Andrei Yafaev (UCL) 19 Feb 2009 Harrison 101 Thursday 3pm Pure Mathematics Professor Professor Nigel Boston (Dublin) 5 Feb 2009 Harrison 101 Thursday 3pm Pure Mathematics Arboreal representations, factoring iterates, and p-extensions Linear growth of rational points on Chatelet surfaces Dr Tim Browning (Bristol university) 29 Jan 2009 Harrison 101 Thursday 3pm Pure Mathematics On Geometry of Hilbert Modular Varieties and Applications to Canonical Subgroups Dr Payman Kassaei (King's College London) 15 Jan 2009 Harrison 101 Thursday 3pm Pure Mathematics p-adic semistable representations and generalization of the Shafarevich Conjecture Professor Victor Abrashkin (Durham University) 3 Dec 2008 Harrison 101 Thursday 3pm Pure Mathematics Breuil’s theory of semistable p-adic representations is applied to prove the following property: if X is a projective variety over Q with semistable reduction modulo 3 and good reduction at all other primes then its Hodge number h^{2,0} = 0 Limits of normal functions and Abel Jacobi maps Matthew Kerr (Durham University) 27 Nov 2008 Harrison 101 Thursday 3pm Pure Mathematics Determinant functors for triangulated categories Dr Manuel Breuning (Kings College) 13 Nov 2008 Harrison 101 Thursday 3pm Pure Mathematics On the Iwasawa theory of abelian varieties over function fields Dr Fabian Trihan (Nottingham university) 6 Nov 2008 Harrison 101 Thursday 3pm Pure Mathematics The Manin constant of elliptic curves over function fields Dr Ambrus Pal (Imperial College) 30 Oct 2008 Harrison 101 Thursday 3pm Pure Mathematics We study the p-adic valuation of the values of normalized Hecke eigenforms attached to non-isotrivial elliptic curves defined over function fields of transcendence degree one over finite fields of characteristic p. Under certain assumptions we compute on the smallest attained valuation in terms of the minimal discriminant. As a consequence we show that the former can be arbitrarily small. We also use our results to prove for the first time the analogue of the degree conjecture unconditionally for infinite families of strong Weil curves defined over rational function fields Almost Koszul algebras from quantum subgroups Dr Barrie Cooper (Exeter University) 23 Oct 2008 Harrison 101 Thursday 3pm Pure Mathematics Algebraic surfaces and hyperbolic geometry Prof. Burt Totaro (Cambridge university) 16 Oct 2008 Harrison 101 Thursday 3pm Pure Mathematics The intersection form among curves on a complex algebraic surface always has signature (1,n) for some n. So the automorphism group of an algebraic surface always acts on hyperbolic (n-1)-space. For a class of surfaces including K3 surfaces and many rational surfaces, there is a close connection between the properties of the variety and the corresponding group acting on hyperbolic space Rational points of definable sets and diophantine problems Dr. Jonhatan Pila (Bristol University) 9 Oct 2008 Harrison 101 Thursday 3pm Pure Mathematics I will discuss problems and results concerning the distribution of rational points on algebraic and, mainly, certain non-algebraic sets in $\RR^n$. More specifically, definable sets in o-minimal structures. I will describe a result, joint with Wilkie, that such a set $X$ can have only few'' rational points, in a density sense, that do not lie on some positive dimensional connected semi-algebraic subset of $X$.I will give some applications to problems of Andre-Oort-Manin-Mumford type, including a new proof, joint with Zannier, of the Manin-Mumford conjecture, and some variant special cases of results of Andre-Oort and mixed Andre-Oort-Manin-Mumford type. Rational points of definable sets and diophantine problems Dr. Jonhatan Pila (Bristol University) 9 Oct 2008 Harrison 101 Thursday 3pm Pure Mathematics I will discuss problems and results concerning the distribution of rational points on algebraic and, mainly, certain non-algebraic sets in $\RR^n$. More specifically, definable sets in o-minimal structures. I will describe a result, joint with Wilkie, that such a set $X$ can have only few'' rational points, in a density sense, that do not lie on some positive dimensional connected semi-algebraic subset of $X$.I will give some applications to problems of Andre-Oort-Manin-Mumford type, including a new proof, joint with Zannier, of the Manin-Mumford conjecture, and some variant special cases of results of Andre-Oort and mixed Andre-Oort-Manin-Mumford type. Eigenvarieties and p-adic Banach spaces Richard Hill (University College, London) 8 May 2008 Harrison 106 Thursday 3pm Pure Mathematics Integral Points on Curves of Higher Genus Samir Siksek (Warwick) 1 May 2008 Harrison 106 Thursday 3pm Pure Mathematics For many curves of higher genus, Baker's Theory provides (astronomical) bounds for the size of integral points. I explain how to combine Baker's bounds with the Mordell-Weil sieve to compute all the integral points on some curves of higher genus. This is based on joint work with Bugeaud, Mignotte, Stoll and Tengely. Modular forms and Galois representations over imaginary quadratic fields Tobias Berger (Cambridge) 13 Mar 2008 Harrison 106 Thursday 3pm Pure Mathematics In joint work with Gergely Harcos I strengthened a result of Taylor on associating Galois representations to cuspforms over imaginary quadratic fields. I further present a result (joint with Kris Klosin) on the modularity of ordinary, residually reducible Galois representations of imaginary quadratic fields. My Evil Determinant Problem Robin Chapman (University of Exeter) 11 Mar 2008 Harrison 103 Tuesday 9am Pure Mathematics (Internal) Fundamental groups of hyperbolic curves and the principle of Birch and Swinnerton-Dyer Minhyong Kim (University College, London) 6 Mar 2008 Harrison 106 Thursday 3pm Pure Mathematics period domains, modular forms and lattices Dr Gregory Sankaran (Bath University) 5 Mar 2008 Harrison 101 Thursday 3pm Pure Mathematics Hopf-Galois Module Structure of Tame Extensions of Prime Power Degree Paul Truman (University of Exeter) 4 Mar 2008 Harrison 103 Tuesday 9am Pure Mathematics (Internal) A major result in local Galois module theory is Noether's Theorem, that given a finite Galois extension of local fields L/K, the ring of integers OL is free over the integral group ring OK[G] if and only L/K is at most tamely ramified. In Hopf-Galois module theory, the Galois group is replaced by a (possibly non-unique) Hopf algebra, giving a so-called Hopf-Galois structure on the extension, and the behaviour of OL in this Hopf-Galois structure is studied. We present a generalisation of Noether's Thereom to this setting for Galois extensions of prime power degree. Arithmetic properties for partitions with non-repeating odd parts James Sellers (Pennsylvania State) 28 Feb 2008 Harrison 106 Thursday 3pm Pure Mathematics Some examples of local Galois module structure in characteristic 0 and characteristic $p$. Nigel Byott (University of Exeter) 26 Feb 2008 Harrison 103 Tuesday 9am Pure Mathematics (Internal) Let $L/K$ be a totally ramified abelian extension of local fields, with Galois group $G$. A basic question in Galois module structure is to determine when the valuation ring $S$ of $L$ is a free module over its associated order in the group algebra $K[G]$. When $K$ is a finite extension of $\mathbb{Q}_p$ (the characteristic $0$ case), Y.~Miyata has given a freeness criterion for a large family of {\em cyclic} extensions of degree $p^n$. In this talk, I will give an alternative formulation of Miyata's criterion, and will present work in progress (joint with Griff Elder), where the same freeness criterion arises for {\em elementary abelian} extensions of the field $K=\mathbb{F}_q((T))$ of formal Laurent series over a finite field (the characteristic $p$ case). Growth in linear algebraic groups: an approach through incidence Harald Helfgott (Bristol) 21 Feb 2008 Harrison 106 Thursday 3pm Pure Mathematics Let K be R, C or a Z/pZ. Let G = SL_2(K). Not long ago, I proved the following theorem: for every subset A of G that is not contained in a proper subgroup, the set A\cdot A\cdot A is much larger than A. A generalisation to groups of higher rank was desired by many, but seemed hard to obtain. I shall now present a proof somewhat different from the first one. The role of both linearity and the group structure of G should now be clearer. A few ideas towards a generalisation will be discussed, with a focus on the case of SL_3(Z/pZ). On The Rank of Classgroups of Quadratic Function Fields Andreas Schwiezer (University of Exeter) 19 Feb 2008 Harrison 103 Tuesday 9am Pure Mathematics (Internal) Semi-stable models of modular curves Adam Joyce (Bristol) 14 Feb 2008 Harrison 106 Thursday 3pm Pure Mathematics The anabelian geometry of Grothendieck Mohamed Saidi (University Of Exeter) 5 Feb 2008 Harrison 103 Tuesday 9am Pure Mathematics (Internal) I will explain what the Grothendieck anabelian conjectures are and how did Grothendieck come to them. I will give an overview on the state of these conjectures and my contribution to the subject. The relative kernel group of an order and SK_1 Steve Wilson (Bristol) 31 Jan 2008 Harrison 106 Thursday 3pm Pure Mathematics Vinogradov's three primes revisited Andrew Booker (Bristol) 5 Dec 2007 Harrison 106 Thursday 3pm Pure Mathematics Self-points on elliptic curves Christian Wuthrich (Nottingham) 29 Nov 2007 Harrison 106 Thursday 3pm Pure Mathematics Siegel modular forms and representation numbers of quadratic forms Lynne Walling (Bristol) 22 Nov 2007 Harrison 106 Thursday 3pm Pure Mathematics Number theorists love to count things, especially integral objects. An example is to count the number of ways an integral quadratic form represents each integer, where the variables of the quadratic form are only allowed to assume integral values. More generally, we can ask to count the number of ways a quadratic form represents a lower dimensional quadratic form. These representation numbers are encoded in the Fourier coefficients of generalized theta series, which are examples of modular forms. When counting representation numbers of integers, the associated theta series is a function of one complex variable, whereas to count representation numbers of rank n quadratic forms, the associated theta series is a function of an n by n symmetric complex matrix. We will discuss these theta series, with particular attention given to the Hecke operators and the information they provide regarding representation numbers. Crystalline representation and F-crystals Fabien Trihan (Nottingham) 16 Nov 2007 Harrison 171 Friday 3pm Pure Mathematics Let K be a complete discrete valuation field of mixed characteristics. Assume its residue field has a finite p-basis. Then there exists an equivalence of category between the category of crystalline representations of the absolute Galois group of K, with Hodge-Tate weights in {0,1} and the Barsotti-Tate groups over the ring oif integers of K. Computing the Brauer-Manin obstruction Martin Bright (Bristol) 1 Nov 2007 Harrison 106 Thursday 3pm Pure Mathematics Hodge structures on homotopy groups Jonathan Pridham (Cambridge) 25 Oct 2007 Harrison 106 Thursday 3pm Pure Mathematics A Jacquet-Langlands correspondence in weight 1 Lloyd Kilford (Bristol) 18 Oct 2007 Harrison 106 Thursday 3pm Pure Mathematics We will give a brief introduction to quaternionic modular forms, and present the results of explicit computations relating quaternionic and classical modular forms of weight 1 (using a form of the Jacquet-Langlands correspondence). This is joint work with Kevin Buzzard Wild ramification in extra-special extensions Griff Elder (Virginia Tech / University of Nebraska at Omaha) 21 Jun 2007 Harrison 106 Thursday 2pm Pure Mathematics It was observed, with J. Hooper, that sharp lower bounds for the largest ramification break number in quaternion extensions of dyadic local number fields depend upon the refined ramification filtration, as defined with N. Byott. Moreover, quaternion counter-examples to the conclusion of Hasse-Arf require that this refined filtration be extreme in two different ways. In this talk, we will extend these results to a more general class of non-abelian extensions that includes extra-special extensions. To keep complications to a minimum, we will work over characteristic $p$ local fields. Statistics of elliptic curves over finite fields Ernst-Ulrich Gekeler (University of Saarbruecken) 24 May 2007 Harrison 106 Thursday 3pm Pure Mathematics Which overconvergent Hilbert modular forms are classical? Shu Sasaki (Imperial College London) 17 May 2007 Harrison 106 Thursday 3pm Pure Mathematics On canonical subgroups of abelian varieties Payman Kassaei (Kings College London) 10 May 2007 Harrison 106 Thursday 3pm Pure Mathematics Witt-groups of constructible derived categories Jonathan Woolf (Liverpool) 3 May 2007 Harrison 106 Thursday 3pm Pure Mathematics On the continuous part of codimension 2 algebraic cycles on certain threefolds Volodya Guletskii (University of Liverpool) 26 Apr 2007 Harrison 106 Thursday 3pm Pure Mathematics TBA Shaun Stevens (East-Anglia) 29 Mar 2007 Harrison 106 Thursday 3pm Pure Mathematics TBA Ahmed Abbes (Paris) 15 Mar 2007 Harrison 106 Thursday 3pm Pure Mathematics Cohomology of locally analytic representations Jan Kohlhaase (Muenster) 9 Mar 2007 Harrison TBA Friday TBA Pure Mathematics On the p-adic elliptic polylogarithm and the two-variable p-adic L-function for an CM-elliptic curve Kenichi Bannai (Nagoya/Paris) 1 Mar 2007 Harrison 106 Thursday 3pm Pure Mathematics Potentially crystalline representaions and p-adic representations of GL_2. Matthias Strauch (Cambridge) 23 Feb 2007 Harrison TBA Friday TBA Pure Mathematics On the continuous part of codimension two algebraic cycles on certain threefolds over a field Volodya Guletskii (University Of Liverpool) 15 Feb 2007 Harrison 106 Thursday 3pm Pure Mathematics Let X be a non-singular projective threefold over a field with resolution of singularities, and let A^2(X) be the group of algebraically trivial codimension 2 algebraic cycles on X modulo rational equivalence with coefficients in Q. Assume X is birationally equivalent to another threefold X' admitting a fibration over a curve whose generic fiber F satisfies the following three conditions: (i) the motive M(F) is finite-dimensional, (ii) for l-adic etale cohomology H^1(F)=0 and (iii) H^2(F) is spanned by divisors on F. We prove that, provided these three assumptions, the group A^2(X) is weakly representable: there exists a curve Y and a correspondence z from Y to X, such that z induces an epimorphism A^1(Y) --> A^2(X), where A^1(Y) is isomorphic to Pic^0(Y) tensored with Q. In particular, the result holds for threefolds birational to three-dimensional Del Pezzo fibrations over a curve. Upper triangular technology and the Arf-Kervaire invariant Victor Snaith (University Of Sheffield) 1 Feb 2007 Harrison 106 Thursday 3pm Pure Mathematics This is a talk about an old topology problem in the theory of the homotopy groups of spheres. I will do my best to make it entertaining for non-specialists with emphasis on (i) mathematical history and (ii) the simple algebra which Upper Triangular Technology transforms the topology in. On McRae's Invariant Prof Peter Vamos (University Of Exeter) 4 Dec 2006 Harrison 209 Monday 3pm Pure Mathematics (Internal) Arithmetic conjectures on algebraic cycles Prof Andreas Langer (University Of Exeter) 20 Nov 2006 Harrison 209 Monday 3pm Pure Mathematics (Internal) Realizable Galois Module Classes for some Nonabelian Extensions Dr Nigel Byott (University Of Exeter) 13 Nov 2006 Harrison 209 Monday 3pm Pure Mathematics (Internal) Hopf-Galois Module Structure Of Tame Biqaudratic Extensions Paul Truman (University Of Exeter) 6 Nov 2006 Harrison 102 Monday 3pm Pure Mathematics (Internal) Syntomic cohomology and explicit reciprocity laws Hannu Harkonen (University of Cambridge) 25 May 2006 Harrison 106 Thursday 5pm Pure Mathematics Serre's conjectures over totally real fields Frazer Jarvis (Sheffield) 25 May 2006 Harrison 106 Thursday 3pm Pure Mathematics Counting Hopf-Galois Structures Nigel Byott (University Of Exeter) 22 May 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) A conjectural relative fixed point formula Damian Roessler (Paris) 18 May 2006 Harrison 106 Thursday 3pm Pure Mathematics The sheaf of overconvergent Witt Vectors Prof Andreas Langer (University Of Exeter) 15 May 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) Rigid syntomic cohomology with coefficients and applications Kenichi Bannai (Paris) 11 May 2006 Harrison 106 Thursday 3pm Pure Mathematics On the torsion of elliptic curves over sufficiently general function fields Andreas Schweizer (University Of Exeter) 8 May 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) Generalized Coleman power series in K2 Sarah Zerbes (Paris) 4 May 2006 Harrison 106 Thursday 3pm Pure Mathematics Equivariant vector-bundles on p-adic symmetric spaces Elmar Grosse-Kloenne (Muenster) 16 Mar 2006 Harrison 106 Thursday 3pm Pure Mathematics P-D Structures Prof Andreas Langer (University Of Exeter) 13 Mar 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) The Ring Of Witt-Vectors Prof Andreas Langer (Universty of Exeter) 6 Mar 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) Galois-module structure of a cyclic extension: on a result of Miyata Nigel Byott (University of Exeter) 23 Feb 2006 Harrison 106 Thursday 3pm Pure Mathematics Galois-module structure of a cyclic extension: on a result of Miyata Nigel Byott (University Of Exeter) 23 Feb 2006 Laver B74 Thursday 3pm Pure Mathematics (Internal) On the power of linear dependences Imre Barany (London) 16 Feb 2006 Harrison 106 Thursday 3pm Pure Mathematics Real K3 surfaces V. Nikulin (Liverpool) 9 Feb 2006 Harrison 106 Thursday 3pm Pure Mathematics Up to deformation, there are three real types of elliptic curves which depend on the number of real ovals: 0, 1 or 2. All elliptic curves are hyper-elliptic, and their real forms can be obtained by the double covering of P^1/R ramified in four points, some of them conjugate. This gives equations of real elliptic curves. K3 surfaces give a 2-dimensional generalization of elliptic curves. What about similar results for them? This will be the subject of the talk. Hopf-Galois Module Structure of Tame Biquadratic Fields Paul Truman (University Of Exeter) 6 Feb 2006 Harrison 103 Tuesday None Pure Mathematics (Internal) Congruence kernels in arithmetic lattices Alec Mason (Glasgow) 2 Feb 2006 Harrison 106 Thursday 3pm Pure Mathematics Polynomial invariants of links, graphs, and matroids S Huggett (Plymouth) 1 Dec 2005 Harrison 106 Thursday 3pm Pure Mathematics We review the relationships between links, graphs, and matroids. In particular, given a planar graph there are two well-established methods of generating an alternating link diagram. Switching from one of these methods to the other corresponds in knot theory to tangle insertion in the link diagrams, and in combinatorics to the tensor product of the cycle matroids of the graphs. We show how the Jones and Tutte polynomials behave under these operations. Heuristic Algorithms in Group Theory M. Craven (Exeter) 24 Nov 2005 Harrison 106 Thursday 3pm Pure Mathematics Stark units, Hilbert symbols and Stickelberger-like ideals at s=1 D. Salomon (Kings College London) 10 Nov 2005 Harrison 106 Thursday 3pm Pure Mathematics Euler-characteristics of nearly perfect complexes B. Koeck (Southampton) 3 Nov 2005 Harrison 106 Thursday 3pm Pure Mathematics Solving conics over function fields J. Cremona (Nottingham) 27 Oct 2005 Harrison 106 Thursday 3pm Pure Mathematics Shared values of meromorphic functions on compact Riemann surfaces A.Schweizer (Exeter) 13 Oct 2005 Harrison 106 Thursday 3pm Pure Mathematics On Tsuzuki's approach to the Crew-conjecture M.Lederer (Innsbruck) 6 Oct 2005 Harrison 106 Thursday 3pm Pure Mathematics Classification of defect Artin-Schreier extensions Franz-Viktor Kuhlmann (Saskatchewan & Newton Inst) 28 Jun 2005 Harrison 106 Tuesday 10am Pure Mathematics Classification of defect Artin-Schreier extensions Franz-Viktor Kuhlmann (Saskatchewan & Newton Inst) 28 Jun 2005 Harrison 106 Tuesday 10am Pure Mathematics Ramification and Galois structure in 1-dimensional elementary abelian local extensions Griff Elder (University of Nebraska at Omaha) 24 Jun 2005 Harrison B93 Friday 3pm Pure Mathematics Faltings's strict modules: a characteristic p analogue of classical finite flat group schemes Victor Abrashkin (Durham) 20 May 2005 Harrison 106 Friday 5pm Pure Mathematics Counting orbits on colourings, flows, and codewords Peter Cameron (Queen Mary) 5 May 2005 Harrison 106 Thursday 3pm Pure Mathematics Inaugural Lecture - The World of Primes since Fermat Professor Andreas Langer (University of Exeter) 28 Apr 2005 Harrison LT3 Thursday 2pm Pure Mathematics Arithmetic progressions of primes Ben Green (Bristol) 17 Mar 2005 Harrison 106 Thursday 3pm Pure Mathematics Green and Tao recently announced a proof of the existence of arbitrarily long finite arithmetic progressions consisting entirely of primes. This is one of the biggest results in number theory in recent years. Ben Green will be talking about this work today. Euler characteristics in relative algebraic K-groups Manuel Breuning (Nottingham) 10 Mar 2005 Harrison 106 Thursday 3pm Pure Mathematics The fundamental group scheme in characteristic p and the conjectures of Nori Vikram Mehta (Tata Institute, Mumbai) 10 Mar 2005 Harrison LT321 Thursday 10am Pure Mathematics The fundamental group of curves in positive characteristic Mohamed Saidi (University of Exeter) 3 Mar 2005 Harrison LT321 Thursday 10am Pure Mathematics On the p-adic regulator of varieties over p-adic fields Dr Noriyuki Otsubo (Paris) 24 Feb 2005 Harrison 106 Thursday 3pm Pure Mathematics Purity for p-divisible groups Prof Thomas Zink (Bielefeld) 24 Feb 2005 Harrison 106 Thursday 5pm Pure Mathematics Topological invariants of singular spaces Burt Totaro (Cambridge) 17 Feb 2005 Harrison 106 Thursday 3pm Pure Mathematics Picard groups of some module categories Peter Vamos (University of Exeter) 3 Feb 2005 Harrison 106 Thursday 3pm Pure Mathematics Random preorders Dudley Stark (Queen Mary) 27 Jan 2005 Harrison 106 Thursday 3pm Pure Mathematics On the Andre-Oort conjecture Andrei Yafaev (University College, London) 9 Dec 2004 Harrison 106 Thursday 3pm Pure Mathematics The Andre-Oort conjecture asserts that the Zariski closure of a set of special points in a Shimura variety is a subvariety of Hodge type. In this talk I will present recent results on this conjecture and an application to the transcendence theory of hypergeometric functions. Iwasawa theory for elliptic curves at supersingular primes Shinuchi Kobayashi (University of Paris) 2 Dec 2004 Harrison 106 Thursday 3pm Pure Mathematics Isotropy of quadratic forms in finite and infinite dimension Detlev Hoffmann (University of Nottingham) 25 Nov 2004 Harrison 106 Thursday 3pm Pure Mathematics Semisymmetric cubic graphs Chris Parker (University of Birmingham) 18 Nov 2004 Harrison 106 Thursday 3pm Pure Mathematics Additive decompositions of the primes Christian Elsholtz (Royal Holloway, University of London) 12 Nov 2004 Harrison LT6 Friday 3pm Pure Mathematics Corings and Galois theory Tomasz Brzezinski (Swansea, University of Wales) 11 Nov 2004 Harrison 106 Thursday 3pm Pure Mathematics Companion forms Toby Gee (Imperial College, London) 4 Nov 2004 Harrison 106 Thursday 3pm Pure Mathematics $p$-groups and semistable reduction of curves Mohamed Saidi (University of Exeter) 28 Oct 2004 Harrison 106 Thursday 3pm Pure Mathematics Introduction to de Rham-Witt cohomology Andreas Langer (University of Exeter) 26 Oct 2004 Harrison B93 Tuesday 3pm Pure Mathematics Beilinson's conjecure for $K_2$ of certain (hyper)elliptic curves Rob de Jeu (University of Durham) 21 Oct 2004 Harrison 106 Thursday 3pm Pure Mathematics To be announced Adam Epstein (Warwick) 27 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Adam Epstein (Warwick) 27 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Daniel Delbourgo (Nottingham) 13 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Daniel Delbourgo (Nottingham) 13 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Alan Camina (UEA) 6 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Alan Camina (UEA) 6 Nov 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Victor Flynn (Liverpool) 30 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Victor Flynn (Liverpool) 30 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Sophie Huczysnka (Edinburgh) 23 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Sophie Huczysnka (Edinburgh) 23 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Tom Korner (Cambridge) 16 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics To be announced Tom Korner (Cambridge) 16 Oct 2003 Harrison 106 Thursday 3pm Pure Mathematics The AKS algorithm Robin Chapman (University of Exeter) 21 May 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) To be announced Rahman Bahmani Sangsari (University of Exeter) 14 May 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) To be announced Julie Fowler (University of Exeter) 7 May 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) Cuntz and Leavitt algebras Peter Vámos (University of Exeter) 30 Apr 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) Infinite Designs Bridget Webb (Open University) 20 Mar 2003 Harrison 106 Thursday 3pm Pure Mathematics Infinite designs are quite rare in the literature--most books on design theory have no mention of them at all. In this talk I will present a brief history of infinite designs, give a precise definition, and compare some properties of finite and infinite designs. Cuntz and Leavitt algebras - (POSTPONED) Peter Vámos (University of Exeter) 19 Mar 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) Convergence groups and Hausdorff dimension James Anderson (Southampton) 13 Mar 2003 Harrison 106 Thursday 3pm Pure Mathematics Asymptotics of class numbers Anton Deitmar (University of Exeter) 12 Mar 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) The McKay correspondence in dimension 3 Alistair King (Bath) 6 Mar 2003 Harrison 106 Thursday 3pm Pure Mathematics Hermitian structures on lattices Robin Chapman (University of Exeter) 5 Mar 2003 Harrison 103 Tuesday None Pure Mathematics (Internal) The Arithmetic of Quadratic Recurrence Sequences Graham Everest (East Anglia) 27 Feb 2003 Harrison 106 Thursday 3pm Pure Mathematics Generalized blocks for symmetric groups Geoffrey Robinson (Birmingham) 20 Feb 2003 Harrison 106 Thursday 3pm Pure Mathematics Paths in the cube Imre Leader (Cambridge) 13 Feb 2003 Harrison 106 Thursday 3pm Pure Mathematics Mapping class groups and Teichmuller spaces William Harvey (King's College) 30 Jan 2003 Harrison 106 Thursday 3pm Pure Mathematics Symmetric squares of elliptic curves: evidence for the Bloch-Kato Conjecture Neil Dummigan (Sheffield) 23 Jan 2003 Harrison 106 Thursday 3pm Pure Mathematics Free Lie algebras as modules for finite groups Ralph Stohr (UMIST) 16 Jan 2003 Harrison 106 Thursday 3pm Pure Mathematics Geometric approach to the distribution of n**2 alpha mod 1 Jens Marklof (Bristol) 5 Dec 2002 Harrison 106 Thursday 3pm Pure Mathematics Functorial aspects of the unit sum number of rings Nahid Ashrafi (University of Exeter) 4 Dec 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Topological invariants for quasicrystals John Hunton (Leicester) 28 Nov 2002 Harrison 106 Thursday 3pm Pure Mathematics Totally and weakly ramified extensions Lee Jackson (University of Exeter) 27 Nov 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Iwasawa algebras and arithmetic John Coates (Cambridge) 21 Nov 2002 Harrison 106 Thursday 3pm Pure Mathematics Non-Abelian Iwasawa Theory and Elliptic Curves, Theory and Examples Susan Howson (Oxford) 14 Nov 2002 Harrison 106 Thursday 3pm Pure Mathematics Simple groups and Hopf-Galois structures Nigel Byott (University of Exeter) 13 Nov 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Topological Hochschild cohomology of noncommutative ring spectra Andrey Lazarev (Bristol) 7 Nov 2002 Harrison 106 Thursday 3pm Pure Mathematics Starks conjecture and new Stickelberger phenomena Vic Snaith (Southampton) 31 Oct 2002 Harrison 106 Thursday 3pm Pure Mathematics Commuting superline maps Ben Mestel (University of Exeter) 30 Oct 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Random matrix theory and L-functions Jon Keating (Bristol) 24 Oct 2002 Harrison 106 Thursday 3pm Pure Mathematics Mixing and Diophantine problems Tom Ward (UEA) 10 Oct 2002 Harrison 106 Thursday 3pm Pure Mathematics Counting subgroups in nilpotent groups and points on elliptic curves Marcus du Sautoy (Oxford) 18 Jun 2002 Harrison 106 Thursday 3pm Pure Mathematics Complex and p-adic Stark Conjectures at s=1 David Solomon (Kings College) 13 Jun 2002 Harrison 106 Thursday 3pm Pure Mathematics 'Invariant extension of automorphic functions, differential intertwining operators and Jacobi polynomials' Andreas Juhl (Stockholm) 6 Jun 2002 Harrison 106 Thursday 3pm Pure Mathematics Conformal geometry and Clifford algebras Fran Burstall (Bath) 30 May 2002 Harrison 106 Thursday 3pm Pure Mathematics The Hasse principle for Diophantine equations Alexei Skorobogatov (Imperial) 23 May 2002 Harrison 106 Thursday 3pm Pure Mathematics Higher power residue codes and unimodular lattices Mehrdad Ahmadzadeh-Raji (University of Exeter) 21 May 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Galois covers of degree p and semi-stable reduction of curves Mohamed Saïdi (Durham) 16 May 2002 Harrison 106 Thursday 3pm Pure Mathematics New quadratic iterations to Pi Heng Huat Chan (National U Singapore) 9 May 2002 Harrison 106 Thursday 3pm Pure Mathematics Constructing Hopf orders to act on valuation rings Julie Fowler (University of Exeter) 7 May 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Pisot numbers and Coxeter graphs Chris Smyth (Edinburgh) 2 May 2002 Harrison 106 Thursday 3pm Pure Mathematics The Kubota symbol on SL_n Richard Hill (UCL) 25 Apr 2002 Harrison 106 Thursday 3pm Pure Mathematics 'Paperfolding, automata, and rational functions' Alf van der Poorten (Sydney) 14 Mar 2002 Harrison 106 Thursday 3pm Pure Mathematics Determining matroid representability over the reals Rosemary Baines (University of Exeter) 12 Mar 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Beyond Borel-Cantelli Maurice Dodson (York) 7 Mar 2002 Harrison 106 Thursday 3pm Pure Mathematics On the matrix type of a ring Rahman BahmaniSangesari (University of Exeter) 5 Mar 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Torsion theory and co-Cohen-Macaulay modules Mohammad Bijan-Zadeh (University of Tehran) 26 Feb 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Polylogarithms and special values of L-functions Guido Kings (Regensburg) 21 Feb 2002 Harrison 106 Thursday 3pm Pure Mathematics Homology decompositions of classifying spaces Dietrich Notbohm (Leicester) 14 Feb 2002 Harrison 106 Thursday 3pm Pure Mathematics Local analogue of the Grothendieck Conjecture Victor Abrashkin (Durham) 7 Feb 2002 Harrison 106 Thursday 3pm Pure Mathematics Realisable classes of wild extensions Lee Jackson (University of Exeter) 5 Feb 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) Rings generated by Eulerian derivatives David Jordan (Sheffield) 31 Jan 2002 Harrison 106 Thursday 3pm Pure Mathematics On globally periodic solutions of the difference equation $x_{n+1} = f(x_n)/x_{n-1}$ Ben Mestel (University of Exeter) 29 Jan 2002 Harrison 103 Tuesday None Pure Mathematics (Internal) 'Ergodic averages, exponential sums and combinatorial number theory' Kit Nair (Liverpool) 24 Jan 2002 Harrison 106 Thursday 3pm Pure Mathematics The Fermat equation over real quadratic fields Frazer Jarvis (Sheffield) 17 Jan 2002 Harrison 106 Thursday 3pm Pure Mathematics Goldbach's conjecture and powers of 2 Roger Heath-Brown (Oxford) 6 Dec 2001 Harrison 106 Thursday 3pm Pure Mathematics A golden mean functional recurrence Ben Mestel (University of Exeter) 4 Dec 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Lower and Upper Bounds in Discrepancy Theory William Chen ('Macquarie University, Sydney') 29 Nov 2001 Harrison 106 Thursday 3pm Pure Mathematics Realisable classes for tame non-abelian extensions of degree 8 Nigel Byott (University of Exeter) 27 Nov 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Schur Weyl duality and tilting theory Steffen Koenig (Leicester) 22 Nov 2001 Harrison 106 Thursday 3pm Pure Mathematics A family of equivariant Fredholm modules Stuart Horswell (University of Exeter) 20 Nov 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Do we really live in a Riemannian world? Dmitri Vassiliev (Bath) 15 Nov 2001 Harrison 106 Thursday 3pm Pure Mathematics A probabilistic proof of the Andrews-Gordon identities Robin Chapman (University of Exeter) 13 Nov 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Transversals in Latin Squares Ian Wanless (Oxford) 8 Nov 2001 Harrison 106 Thursday 3pm Pure Mathematics Endomorphisms of free modules of infinite rank Peter V'{a}mos (University of Exeter) 6 Nov 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Probability and learning Igor Rivin (Manchester) 25 Oct 2001 Harrison 106 Thursday 3pm Pure Mathematics Mellin transforms of Whittaker functions Anton Deitmar (University of Exeter) 23 Oct 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Rings of injective dimension 1 Arthur Chatters (Bristol) 18 Oct 2001 Harrison 106 Thursday 3pm Pure Mathematics Saturating Mordell-Weil groups John Cremona (Nottingham) 11 Oct 2001 Harrison 106 Thursday 3pm Pure Mathematics Are there any (interesting) non-commutative Hopf orders? Nigel Byott (University of Exeter) 26 Jun 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) From matroids to equations and back Peter Vamos (University of Exeter) 19 Jun 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Families of modular forms Kevin Buzzard (Imperial College) 14 Jun 2001 Harrison 106 Thursday 3pm Pure Mathematics Generalizing the analytic class number formula Annette Huber-Klawitter (Leipzig) 7 Jun 2001 Harrison 106 Thursday 3pm Pure Mathematics Quantisations of Kleinian Singularities and Beyond Dmitriy Rumynin (Warwick) 31 May 2001 Harrison 106 Thursday 3pm Pure Mathematics Refined class number formulas for abelian L-functions David Burns (King's College) 24 May 2001 Harrison 106 Thursday 3pm Pure Mathematics Lefschetz formulae for dynamical systems Anton Deitmar (University of Exeter) 22 May 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Principal homogeneous spaces for some Hopf orders Silvia Sommaro (University of Exeter) 15 May 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Bending Kleinian Groups Caroline Series (Warwick) 10 May 2001 Harrison 106 Thursday 3pm Pure Mathematics Invariant distributions on limit sets Martin Olbrich (Goettingen) 3 May 2001 Harrison 106 Thursday 3pm Pure Mathematics Bizarre q-series identities Robin Chapman (University of Exeter) 1 May 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) One hundred years of normal numbers Glyn Harman (Royal Holloway) 26 Apr 2001 Harrison 106 Thursday 3pm Pure Mathematics The 200th proof of quadratic reciprocity? Robin Chapman (University of Exeter) 20 Mar 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Symmetric powers of Galois modules Bernhard Koeck (University of Southampton) 15 Mar 2001 Harrison 106 Thursday 3pm Pure Mathematics Galois Module Structure of some non-normal extensions (of p-adic fields) Julie Fowler (University of Exeter) 13 Mar 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Rings having finite unit sum number Nahid Ashrafi (University of Exeter) 8 Mar 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Derangements and (0,1) matrices with line sum 2 Douglas Rogers 6 Mar 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Characteristic classes of surface bundles Ulrike Tillmann (University of Oxford) 1 Mar 2001 Harrison 106 Thursday 3pm Pure Mathematics Higher power residue codes and the Leech lattice Mehrdad Ahmadzadeh-Raji (University of Exeter) 27 Feb 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Prehomogeneous vector spaces and the trace formula Werner Hoffman (University of Berlin) 22 Feb 2001 Harrison 106 Thursday 3pm Pure Mathematics Almost Unique Factorisation Domains Peter V'{a}mos (University of Exeter) 20 Feb 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Probabilistic structures in Dynamics Stefano Luzatto (Imperial College) 15 Feb 2001 Harrison 106 Thursday 3pm Pure Mathematics Crystallographic groups and Milnor's conjecture Dietrich Burde (Dusseldorf) 13 Feb 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Cyclic homology and the Baum-Connes conjecture Michael Puschnigg (University of Munster) 8 Feb 2001 Harrison 106 Thursday 3pm Pure Mathematics Krull-Schmidt theorem, Goldie dimensions and uniserial modules Alberto Facchini (University of Padua) 6 Feb 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) The matrix group recognition project Charles Leedham-Green (QMW) 1 Feb 2001 Harrison 106 Thursday 3pm Pure Mathematics Class numbers of cubic orders Anton Deitmar (University of Exeter) 30 Jan 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Rational Points Close to Curves Martin Huxley (University of Cardiff) 25 Jan 2001 Harrison 106 Thursday 3pm Pure Mathematics A contraction mapping proof of Schroeder's theorem Ben Mestel (University of Exeter) 23 Jan 2001 Harrison 103 Tuesday None Pure Mathematics (Internal) Symmetric group representations Gordon James (Imperial College) 18 Jan 2001 Harrison 106 Thursday 3pm Pure Mathematics Integration on non-locally compact spaces and local L-functions of arithmetic schemes Ivan Fesenko (University of Nottingham) 11 Jan 2001 Harrison 106 Thursday 3pm Pure Mathematics