Topic: |
tba |
Date: |
14.10.19 |
Time: |
16:15 |
Place: |
H6 |
Guest: |
|
Universität Paderborn |
|
Abstract: |
|
Contact person: |
Topic: |
tba |
Date: |
18.10.19 |
Time: |
16:15 |
Place: |
V3-201 |
Guest: |
|
Max-Planck-Institut für Gravitationsphysik, Potsdam |
|
Abstract: |
|
Contact person: |
Topic: |
The Large-scale Structure of our Universe with Radio galaxies |
Date: |
20.09.19 |
Time: |
14:15 |
Place: |
D6-135 |
Guest: |
|
NAOC Beijing |
|
Abstract: |
The ``Cosmological Principle'' assumes homogeneity and isotropy at large distance scales. This is a fundamental assumption in our standard cosmological framework and therefore must be tested explicitly by observations. In this talk, I will review some great (bizarre, famous, significant!) observations of large scale isotropy/anisotropy achieved by employing radio galaxy surveys. In particular I will present the radio galaxy number count dipole and the latest dipole?quadruple?octopole alignment results from NVSS+SUMSS catalogs. I will discuss a few more observations of large scale isotropy/anisotropy and the existing theoretical proposals to explain these. At present there are several major radio galaxy observations available e.g. LOFAR surveys, TGSS, GLEAM etc. and we have a lot to explore from these observations, later on we are going to have Square Kilometre Array (SKA) observations. With SKA all radio physics is going to benefit immensely, will discuss how much improvement we are expecting to have on isotropy/anisotropy observations with upcoming SKA observations. |
Contact person: |
Topic: |
Next-neighbor particle-particle interaction of fermions in quasi-one-dimensional flat-band lattices |
Date: |
22.07.19 |
Time: |
14:15 |
Place: |
D5-153 |
Guest: |
Simon Tilleke |
Bielefeld University |
|
Abstract: |
|
Contact person: |
Topic: |
Critical behaviour and characteristic polynomials of non-Hermitian random matrices |
Date: |
23.05.19 |
Time: |
16:15 |
Place: |
D5-153 |
Guest: |
|
University of Sussex |
|
Abstract: |
I will discuss some recent developments regarding the normal matrix model. In particular my interest will be in certain critical models where the limiting support of the eigenvalues can radically change its topology by slightly adjusting an external parameter. I will discuss how aspects of the model can be explicitly mapped to the study of expectations of characteristic polynomials of non-Hermitian random matrices (e.g. Ginibre or truncated unitary). Many of these averages are related to Painlevé transcendents, and by exploiting this, a precise and non-trivial asymptotic expansion of partition functions can be calculated in the critical models. This is joint work with Alfredo Deaño (University of Kent). |
Contact person: |
Topic: |
Eigenvalue Spacings of Random Matrices compared to Locations of Buzzard Nests |
Date: |
04.07.19 |
Time: |
14:15 |
Place: |
D5-153 |
Guest: |
Rebecca Werdehausen |
Bielefeld University |
|
Abstract: |
The territorial behavior of buzzards suggests a repulsion between the nests that may match with the repulsion between complex eigenvalues of non-hermitian random matrices. The Ginibre ensemble and the nearest neighbor spacings of the two-dimensional eigenvalues will be introduced and compared to the Poissonian Process in the plane. Then we will calculate the spacings between buzzard nests and the Kolmogorov distance to both theoretical curves. For this aim, the unfolding of the data set is indispensable, so that areas of high human settlement do not influence the spacing statistics. Two different unfolding methods in 2D will be tested and applied. |
Contact person: |