# This Week

Here is a selection of seminars that might be of interest to string theorists in Oxford:

On Monday, March 19, at 14:30 in L6, a seminar in
the Twistor Workshop series:

Matteo Parisi (Oxford)

Landau Singularities

On Wednesday, March 21, at 15:30 in L5, a seminar in
the Number Theory series:

Florian Pop (University of Pennsylvania)

Joint NT/LO Seminar: Rational points and ultrproducts

*There is a conjecture by Colliot-Thelene (about 2005) that under specific hypotheses, a morphism of Q-varieties f : X --> Y has the property that for almost all prime numbers p, the corresponding map X(Q_p) --> Y(Q_p) is surjective. A sharpening of the conjecture was solved by Denef (2016), and later, 'if and only if' conditions on f were given by Skorobogatov et al. The plan for the talk is to explain in detail the conjecture and the results mentioned above, and to report on work in progress on a different method to attack the conjecture under quite relaxed hypotheses.*

**Further information:**