# All Upcoming Events

On Tuesday at 11:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Katy Clough (King's College)

Robustness of Inflation to inhomogeneous initial conditions

On Monday, October 9, at 12:45 in L3, a seminar in
the String Theory series:

Shehryar Sikander (ICTP)

TBA

On Monday, October 9, at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

Ian Heywood (CSIRO)

TBD (Radio Continuum Surveys)

On Monday, October 9, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Frances Kirwan (Oxford)

TBA

On Thursday, October 12, at 16:00 in L6, a seminar in
the Number Theory series:

Alexander Betts (Oxford)

TBA

On Monday, October 16, at 12:45 in L3, a seminar in
the String Theory series:

Lotte Hollands (Herriot-Watt University, Edinburgh)

TBA

On Monday, October 16, at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

Jasson Hessels (ASTRON)

TBD (Pulsars)

On Monday, October 16, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Lorenzo Foscolo (Heriot Watt University)

TBA

On Tuesday, October 17, at 11:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Andreu Font (UCL)

Studying the Expansion of the Universe with quasar spectra

On Thursday, October 19, at 16:00 in L6, a seminar in
the Number Theory series:

Trevor Wooley (University of Bristol)

Smooth values of polynomials

*Recall that an integer n is called y-smooth when each of its prime divisors is less than or equal to y. It is conjectured that, for any a>0, any polynomial of positive degree having integral coefficients should possess infinitely many values at integral arguments n that are n^a-smooth. One could consider this problem to be morally “dual” to the cognate problem of establishing that irreducible polynomials assume prime values infinitely often, unless local conditions preclude this possibility. This smooth values conjecture is known to be true in several different ways for linear polynomials, but in general remains unproven for any degree exceeding 1. We will describe some limited progress in the direction of the conjecture, highlighting along the way analogous conclusions for polynomial smoothness. Despite being motivated by a problem in analytic number theory, most of the methods make use of little more than pre-Galois theory. A guest appearance will be made by several hyperelliptic curves. [This talk is based on work joint with Jonathan Bober, Dan Fretwell and Greg Martin].*

**Further information:**
On Friday, October 20, at 14:30 in L1, a seminar in
the Math Colloquium series:

Peter Sarnak (Princeton University)

Integer points on affine cubic surfaces

*A cubic polynomial equation in four or more variables tends to have many integer solutions, while one in two variables has a limited number of such solutions. There is a body of work establishing results along these lines. On the other hand very little is known in the critical case of three variables. For special such cubics, which we call Markoff surfaces, a theory can be developed. We will review some of the tools used to deal with these and related problems. Joint works with Bourgain/Gamburd and with Ghosh*

**Further information:**
On Friday, October 20, at 16:00 , a seminar in
the Math Colloquium series:

Robert Calderbank (Duke University)

Title tbc

*Tbc*

**Further information:**
On Monday, October 23, at 12:45 in L3, a seminar in
the String Theory series:

Heeyeon Kim (Oxford)

TBA

On Monday, October 23, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Nicholas Sheridan (Cambridge)

Cubic fourfolds, K3 surfaces, and mirror symmetry

*While many cubic fourfolds are known to be rational, it is expected that the very general cubic fourfold is irrational (although none have been proven to be so). There is a conjecture for precisely which cubics are rational, which can be expressed in Hodge-theoretic terms (by work of Hassett) or in terms of derived categories (by work of Kuznetsov). The conjecture can be phrased as saying that one can associate a `noncommutative K3 surface' to any cubic fourfold, and the rational ones are precisely those for which this noncommutative K3 is `geometric', i.e., equivalent to an honest K3 surface. It turns out that the noncommutative K3 associated to a cubic fourfold has a conjectural symplectic mirror (due to Batyrev-Borisov). In contrast to the algebraic side of the story, the mirror is always `geometric': i.e., it is always just an honest K3 surface equipped with an appropriate Kähler form. After explaining this background, I will state a theorem: homological mirror symmetry holds in this context (joint work with Ivan Smith).*

**Further information:**
On Tuesday, October 24, at 11:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Simon Foreman (CITA)

TBD

On Thursday, October 26, at 16:00 in L6, a seminar in
the Number Theory series:

Arthur Forey (Institut de mathématiques de Jussieu)

Joint Number Theory / Logic Seminar: TBA

On Monday, October 30, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Markus Upmeier (Oxford)

Almost Kähler 4-manifolds of Constant Holomorphic Sectional Curvature are Kähler

*We show that a closed almost Kähler 4-manifold of globally constant holomorphic sectional curvature k<=0 with respect to the canonical Hermitian connection is automatically Kähler. The same result holds for k < 0 if we require in addition that the Ricci curvature is J-invariant. The proofs are based on the observation that such manifolds are self-dual, so that Chern–Weil theory implies useful integral formulas, which are then combined with results from Seiberg–Witten theory.*

**Further information:**
On Tuesday, October 31, at 11:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Mark Hindmarsh (Sussex)

TBD

On Thursday, November 2, at 16:00 in L6, a seminar in
the Number Theory series:

Christopher Skinner (Princeton)

TBA

On Monday, November 6, at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

Anthony Beasley (NRAO)

TBD (Radio astronomy)

On Thursday, November 9, at 16:00 in L6, a seminar in
the Number Theory series:

Daniel Loughran (Manchester)

TBA

On Monday, November 13, at 14:00 in Dennis Sciama Lecture Theatre, a seminar in
the Astrophysics Colloquia series:

Avishai Dekel (The Hebrew University Jerusalem)

TBD (Galaxy evolution)

On Monday, November 13, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Mehdi Yazdi (Oxford)

TBA

On Tuesday, November 14, at 23:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Joseph Zuntz (Royal Observatory Edinburgh)

TBD

On Monday, November 20, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Ben Davison (University of Glasgow)

TBA

On Tuesday, November 21, at 11:30 in BIPAC seminar room, a seminar in
the Cosmology series:

Massimo Meneghetti (Bologna)

TBD

On Thursday, November 23, at 16:00 in L6, a seminar in
the Number Theory series:

Anna Cadoret (Ecole Polytechnique (CMLS))

TBA

On Monday, November 27, at 14:15 in L4, a seminar in
the Geometry and Analysis series:

Matthias Wink (Oxford University)

TBA

On Tuesday, November 28, at 11:30 in DWB, a seminar in
the Cosmology series:

Silvia Galli (IAP)

TBD

On Thursday, November 30, at 16:00 in L6, a seminar in
the Number Theory series:

Sam Chow (York)

TBA