This term, all seminars take place Thursdays at 2pm, room MS.04 (Zeeman Building), unless indicated otherwise.



Schedule for

Reimer Kuehn, 30.10.2014

Seminars

05.10.2017 Yan Fyodorov (Kings College)
Exponential number of equilibria and depinning threshold for a directed polymer in a random potential.
Using the Kac-Rice approach, we show that the mean number of all possible equilibria of an elastic line (directed polymer), confined in a harmonic well and submitted to a quenched random Gaussian potential, grows exponentially ~exp(Lr) with its length L. The growth rate is found to be directly related to the generalized Lyapunov exponent of an associated Anderson localization problem of a 1d Schroedinger equation in a random potential. For strong confinement, the rate r is small and given by a non-perturbative (instanton) contribution to the Lyapunov exponent. For weak confinement, the rate r is found to be proportional to the inverse Larkin length of the pinning theory. As an application, identifying the depinning with a landscape ”topology trivialization” phenomenon, we obtain an upper bound for the depinning threshold f_c, in presence of an applied force. The presentation is based on the joint work arXiv:1703.10066 with P.Le Doussal, A. Rosso and C. Texier.
Contact: Nikos
12.10.2017 Alexandre Stauffer (University of Bath)
TBA

Contact: Daniel
19.10.2017 Vladislav Vysotskiy (University of Sussex)
TBA

Contact: Daniel
26.10.2017 Costanza Benassi (University of Warwick)
TBA

02.11.2017 Nils Berglund (Université d Orléans)
TBA

Contact: Hendrik
09.11.2017 Sergio Yuhjtman (University of Buenos Aires)
TBA

Contact: Daniel
16.11.2017 Adam Bowditch (University of Warwick)
TBA

23.11.2017


30.11.2017 Enrico Scalas (University of Sussex)
TBA

Contact: Daniel
07.12.2017