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Aktuelle Veranstaltungen

 

Kolloquium

Thema:

Arbeitsgruppenvorstellung

Datum:

06.12.22

Uhrzeit:

14:15

Ort:

H6

Vortragender:

Dozenten der Physik

Inhalt:

Ansprechpartner:

Fachschaft

Kolloquium Mathematische Physik

Thema:

tba

Datum:

13.01.23

Uhrzeit:

16:15

Ort:

D5-153

Vortragender:

Felix Finster

Universität Regensburg

Inhalt:

Ansprechpartner:

G. Akemann

Seminar Hochenergiephysik

Thema:

Relativistic dynamics in black hole systems and efforts toward the discovery of nano-Hz GWs

Datum:

12.12.22

Uhrzeit:

16:15

Ort:

D6-135

Vortragender:

Prerna Rana

TIFR Mumbai

Inhalt:

The study of bound particle trajectories around a rotating black hole is crucial to understanding many as- trophysical phenomena. I will present a new closed-form analytic solution for the generalized non-equatorial eccentric bound particle trajectories, and their fundamental frequencies, in the Kerr spacetime using general relativity. The trajectories are expressed in the eccentricity, inverse-latus rectum, spin, and Carter’s constant (e, ?, a, Q) parameter space. The generalized solutions also enabled us to obtain the necessary bound orbit conditions for (e, ?, a, Q) and novel specialized formulae for equatorial, spherical, and non-equatorial sepa- ratrix orbits. Next, I will present the Generalized Relativistic Precession Model (GRPM), which utilizes the analytic solutions of trajectories in the Kerr spacetime, to explain the origin of Quasi-periodic oscillations (QPOs) in black hole X-ray binaries (BHXRB). Our analysis of the plasma fluid flow around a Kerr black hole in the relativistic disk edge suggests that instabilities cause QPOs to originate in a torus region spanned by geodesics. The application of the GRPM will also be shown for X-ray QPOs seen in Seyferts galaxies. Toward the end, I will discuss our recent efforts for the first official data release of the Indian Pulsar Timing Array (InPTA), which will be incorporated into the global effort of the International Pulsar Timing Array (IPTA) consortium to discover nano-Hz gravitational waves emitted by the relativistic supermassive black hole binaries.

Ansprechpartner:

D. Schwarz

Seminar Kondensierte Materie

Thema:

Ein Vergleich von kleinen klassischen und quantenmechanischen Spinsystemen

Datum:

01.12.22

Uhrzeit:

14:15

Ort:

D5-153

Vortragender:

Jonas Steffan

Universität Bielefeld

Inhalt:

Ansprechpartner:

Jürgen Schnack

Seminar Mathematische Physik

Thema:

String-localized quantum fields and some phenomenological applications

Datum:

01.12.22

Uhrzeit:

16:00

Ort:

D5-153

Vortragender:

José Gracia Bondia

University of Zaragoza, Spain

Inhalt:

Over fifteen years ago, on the basis of modular theory, string-localized quantum fields (SLQF) were developed by Mund, Rehren, Schroer and Yngvason. There were precedents for them, particularly in work by Buchholz and Fredenhagen towards the end of last century. On the theoretical side, SLQFallow to deal with Wigner particles not covered by Wightman's axioms. They provide as well for new viewpoints and techniques in the phenomenology of the Standard Model.

Ansprechpartner:

Gernot Akemann

Seminar Bielefeld-Melbourne Zufallsmatrizen

Thema:

Moments and SU(N) algebra for Embedded Unitary Ensemble

Datum:

07.12.22

Uhrzeit:

09:00

Ort:

ZOOM / Konferenzschaltung

Vortragender:

V.K.B. Kota

Physical Research Laboratory Ahmedabad

Inhalt:

Embedded random matrix ensembles with $k$-body interactions, usually called EE($k$), introduced 50 years back in the context of nuclear shell model, are now well established to be appropriate for understanding statistical properties of many quantum systems [1]. Say $m$ fermions (or bosons) are in $N$ degenerate single particle states and interacting with $k$-body interactions. Then, with direct product representation of the many-particle states, the $k$ and $m$ fermion space dimensions are $\binom{N}{k}$ and $\binom{N}{m}$ respectively. Now, with a GUE representation for the Hamiltonian ($H$) matrix in the $k$ particle space, the $m$-particle $H$ matrix will be EGUE($k$) - embedded GUE with $k$-body interactions. Similarly, we have EGOE($k$) and EGSE($k$). Note that for $k=m$ we have the classical GOE, GUE and GSE. Recently, using the formulas for the moments up to order 8, it is established that the one-point function, ensemble averaged density of eigenvalues, follows the so called $q$-normal distribution for EGUE($k$) [also for EGOE($k)] with $q$ defined by the fourth moment [2]. The $q$-normal generates Gaussian density for $k << m$ and semi-circle for $k=m$. Unlike the one-point function, till today there is no success in deriving the two-point correlation function for EGUE($k$) or EGOE($k$) even in the limit of $k <

Ansprechpartner:

Mario Kieburg



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