|Friday 23 February 2024
|Events for day: Wednesday 21 February 2024
| 11:00 - 12:00 Wednesday Weekly Seminar - meeting
Revisiting the stochastic QCD axion window: departure from equilibrium during inflation
PARTICLES AND ACCELERATORS
If dark matter is made of QCD axions, its abundance is determined by the vacuum expectation value acquired by the axion field during inflation. The axion is usually assumed to follow the equilibrium distribution arising from quantum diffusion during inflation. This leads to the so-called stochastic window under which the QCD axion can make up all the dark matter. However, in realistic inflationary potentials, I will show that the axion never reaches the equilibrium distribution at the end of inflation. This is because the relaxation time of the axion is much larger than the typical time scale over which the Hubble exp ...
12:45 - 13:45 Geometry and Differential Equations Seminar
Channel CMC Surfaces in Hyperbolic Space
We study and give a complete classification of channel CMC surfaces in hyperbolic space. Our classification consists of explicit parametrizations of these surfaces via elliptic functions and integrals that are pre-implemented in most visualization software and thus easy to use. To accomplish these results, we utilize the setup from Lie sphere geometry. The advantage of our approach is that it directly generalizes and can be used to obtain similar results in other Riemannian and Lorentzian space forms.
13:30 - 15:00 Weekly Seminar
The art of gluing space-time manifolds: methods and applications
Reza Mansouri's book on the development of the expert professor Dr. Reza Mansouri in the field of general relativity and cosmology was published by Springer. In this speech, the topic and content of this book will be explained ...
14:00 - 15:00 Combinatorics and Computing Weekly Seminar
Limit structures in Model theory (II)
Following my previous talk in math colloquium in which I explained the ultraproduct construction, in this talk, I will further discuss another important model-theoretic construction, namely Fraisse-Hrushovski construction . I will then overview some of the applications of this construction in the field of combinatorics.
Meeting ID: 896 0036 6073
Venue: Niavaran, Lecture Hall 1 ...
14:00 - 15:00 Weekly Seminar
Simulating the dynamics of nano water droplets on different surfaces
The dynamics and spreading of nano water droplets on different surfaces have received significant attention due to their potential applications, such as self-cleaning surfaces, water condensation in solids, water collection and transportation, heat transfer during condensation, and energy harvesting. Changes in the wettability of surfaces can have considerable consequences on nanofluid properties, making the application of wetting control parameters useful in designing related nanofluid devices. Atomistic simulation methods, such as the molecular dynamics (MD) simulation method, provide a powerful approach to studying these phenomena and can ...
16:00 - 17:00 Mathematics Colloquium
Distribution of Irreducible Polynomials over Finite Fields
Finite fields are indispensable to modern cryptography and coding theory. It is well known that the implementation of the arithmetic of finite fields greatly depends on their representation, which in turn depends on the existence of irreducible polynomials of special forms. So, studying irreducible polynomials over finite fields besides having a natural theoretical appeal, has an applied appeal, too. There are an abundant number of known results and open problems about the distribution of irreducible polynomials over finite fields. In this talk, we briefly survey what is known and what remains to be explored.
Subscribing the Ma ...