IPM Calendar 
Sunday 21 April 2024   Today  
Events for day: Wednesday 17 April 2024    
           11:00 - 12:00     Wednesday Weekly Seminar - meeting
Luminosity at LHC



Luminosity, along with the center of mass energy, is the most important figure of merit of any particle collider. It quantifies the power of a machine to squeeze particles through a given space in a given time. The precision luminosity measurement is crucial as it directly affects the other physics parameters like physics process's production cross section. In this talk the luminosity is first introduced. Then the technique used to measure this quantity is presented, which yields in determining a calibration constant; so-called sig_{visible}, via some specific van-der-Meer (vdM) scans. Finally, the contribution from s ...

           13:30 - 15:00     Weekly Seminar
Modelling Phenomena in Modern Astrophysics: Binary Stars


This talk is devoted to giving non-specialists an idea of how modern theoretical astrophysicists approach modelling astronomical phenomena. This will be achieved by using the problem of binary stellar evolution as a case study. After a brief introduction on the current relevance of accurately simulating binary stars and a quick glance at stellar evolution, I will discuss several codes that could be used to simulate binary stars, as well as their shortcomings. Then, I will introduce a novel method we devised that could be used to simulate the gravitational fields of binary systems in one-dimensional codes. Afterwards, I will describe a numeric ...

           14:00 - 15:00     Combinatorics and Computing Weekly Seminar
On Variants of Tverberg's Theorem.


The classical Tverberg's theorem of 1966 states that any set of size (d+1)(q-1)+1 in the Euclidean space of dimension d can be partitioned into q parts whose convex hulls intersect. In this talk, I will talk about many variants of this theorem and a conjecture by Engstrom and Noren that was recently proved with the aid of Najafian, ALipour, and Mazidi.

Zoom room information is:
Meeting ID : 896 0036 6073
Passcode : 290109
Venue: Niavaran, Lecture Hall 1 ...

           17:30 - 19:00     Algebraic Geometry Biweekly Webinar
Motives of Stacks of Bundles and Sheaves on Curves


The geometry of moduli spaces and stacks of vector bundles on curves have been intensively studied from different perspectives; for example, via point counting over finite fields by Harder and Narasimhan, and gauge theoretically by Atiyah and Bott over the complex numbers. Following Grothendieck's vision that a motive of an algebraic variety should capture many of its cohomological invariants, Voevodsky introduced a triangulated category of motives which partially realises this idea. After describing some properties of this category, I will present a formula for the motive of the moduli stack of vector bundles on a smooth projective curve; th ...