# Talks

| Talks 1 to 10 of 343 | show all |

Date Time Venue Talk
06/28/18 03:45 pm Am Schwarzenberg-Campus (D), Room D1.021 A minimax principle in spectral gaps*
Albrecht Seelmann, Fakultät für Mathematik - Technische Universität Dortmund

In [Doc. Math. 4 (1999),275--283], Griesemer, Lewis, and Siedentop devised an abstract minimax principle for eigenvalues in spectral gaps of perturbed self-adjoint operators. We show that this minimax principle can be adapted to the particular situation of bounded additive perturbations with hypotheses that are easier to check in this case. The latter is demonstrated in the framework of the Davis-Kahan sin(2\Theta) theorem.

This talked is based on joint work with I. Nakic, M. Täufer, M. Tautenhahn, and I. Veselic.
06/21/18 03:30 pm Am Schwarzenberg-Campus 5 (H), Room H0.05 Poisson local eigenvalue statistics for continuum random Schrödinger operators
Adrian Dietlein, LMU München, Mathematisches Institut

model, with a focus on Minami's estimate and its applications. In
particular it implies Poissonian local eigenvalue statistics, which
is believed to be a characteristic feature of spectrally localized
quantum mechanical systems. In the second part of the talk I'll
present our main technical result, a level-spacing estimate for
continuum random Schrödinger operators, and argue why it implies
Poissonian local eigenvalue statistics. If time permits I'll comment
on the proof's methods.
The talk is based on joint work with Alexander Elgart.
06/07/18 03:45 pm tba Silvestre-Caffarelli approach to Fractional Powers of Linear Operators*
Jan Meichsner

We are going to discuss (again) the approach of describing fractional powers of linear operators on
Banach spaces as it was performed by Silvestre and Caffarelli when they were studying the fractional
Laplacian. Even though useful it is still an open problem whether this is possible for all sectorial
operators and, if so, whether it is unique.
The presented content is work in progress.
05/28/18 01:00 pm Am Schwarzenberg-Campus 3 (E), Room 3.074 Predicting Companies Mentioned in News Articles, a Comparison of Two Approaches: Latent Dirichlet Allocation with k-Nearest Neighbor versus Bag of Words with k-Nearest Neighbor [Projektarbeit]
Max Lübbering
05/17/18 04:30 pm TUHH, Building A, Room A0.19 On the stability of Prony's method*
Stefan Kunis, Institut für Mathematik, Uni Osnabrück
05/16/18 09:30 am Am Schwarzenberg-Campus 3 (E), Room 3.074 Kantenerhaltendes Entrauschen mittels bilateraler Filter [Bachelorarbeit]
Leon Haag, Studiengang TM
05/14/18 01:00 pm Am Schwarzenberg-Campus 3 (E), Room 3.074 A Comparison of Distance Metrics in Collaborative Recommender Systems [Projektarbeit]
The study of electromagnetic fields in 2D circuits often leads to resonances. We use a polynomial chaos expansion (due to uncertain circuit parameters), which is analytically and numerically troublesome near the resonance frequencies. As a toy model for the convergence of the polynomial chaos expansion, we look at the parallel RLC circuit with uncertain capacitance and give $L^2$ error bounds depending on the degree of the expansion, the random distribution, the distance to resonance and the so-called quality factor of the circuit (which is a measure for the damping).