| Saturday 20 April 2024 | |
| Events for day: Wednesday 06 March 2019 |
| 13:30 - 15:00 Weekly Seminar Charged Vector Inflation School ASTRONOMY In this talk we present a model of inflation in which the inflaton field is a complex scalar field charged under a triplet of U(1) gauge fields. We decompose the perturbations into the adiabatic and entropy modes and calculate the curvature perturbation power spectrum and its cross-correlation to entropy modes. In addition to the metric tensor perturbations, there are tensor perturbations associated with the gauge field perturbations which are coupled to metric tensor perturbations. We show that the correction in primordial gravitational tensor power spectrum induced from the matter tensor perturbation is a sensitive function of the gauge cou ... 14:00 - 15:00 Weekly Seminar Composite quasiparticles in ultra-cold dipolar Fermi gases School NANO SCIENCES Composite quasiparticles in ultra-cold dipolar Fermi gases Abstract: Dipolar quantum gases, thanks to their long-range and anisotropic dipole-dipole interactions, are excellent candidates for the exploration of quantum many-body behaviors. Many different exotic phenomena have been predicted for ultra-cold systems of dipolar bosons and fermions. Experimental advances in trapping and cooling polar molecules and magnetic atoms have been impressive too. In this talk, first I will review the ground-state properties of a two-dimensional system of dipolar fermions. Then, I will discuss quasiparticle properties and ... 15:30 - 17:00 Geometry and Topology Weekly Seminar Non-statistical dynamics; Conditions implying the existence, consequences of non-existence School MATHEMATICS For a dynamical system, to be non-statistical means that as the time tends to infinity, the dynamics does not shows convergent statistical behavior in the sense of Birkhoff averages. In this lecture, first we introduce some examples of this kind of behavior in different family of dynamics. Next, we explain the connection between this dynamical behavior and another one called "statistical instability", and show that in any family of dynamical systems, the existence of a "large" set of statistically unstable maps, implies the existence of non-statistical ones. And finally, we present a consequence of this fact for the family of maps that a prio ... 15:30 - 16:30 Weekly Seminar Economic problems of the country; an analysis based on physics and complexity sciences School PARTICLES AND ACCELERATORS Abstract: Economy of the country has faced serious problems which range from decline in gross domestic product (GDP) to depreciation of Rial. In this talk we look over these problems from the viewpoint of physics, economics, and complexity sciences. We first briefly review the history of economy. We then see how a group of economists have been borrowing concepts developed in statistical physics and complexity sciences to improve their understanding about economy. Then we analyze the current conditions of our economy from such view point. We claim that our economy has entered a new phase which we call it a “frozen phase of economy”. We as well ... 16:30 - 18:00 Physics Colloquium "Landau and Ginzburg" remove tensions between "Planck" and "Hubble and Lyman" School PHYSICS Lecture room C, Farmanieh building ... |