"Theory of Particle Physics and Cosmology" Seminar
2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025
2019-03-28 (Thursday)
room 1.01, Pasteura 5 at 12:15 
Stanisław D. Głazek (IFT UW)Gluon string collisions in colliders
I will explain the estimate [1] that collisions of gluon strings can cause azimuthal variation on the order of one to ten percent in the multiplicity and elliptic flow in peripheral proton-proton scattering at LHC. Since according to the estimate the strings are formed inside photons, measurements of the string effects at LHC or other colliders could possibly tell us a bit about how photons are made. [1] Glazek,Brodsky,Goldhaber,Brown,PRD 97,114021('18).
2019-03-14 (Thursday)
room 1.01, Pasteura 5 at 12:15
Ewa Łokas (CAMK Warszawa)Tidally induced bars in interacting galaxies
I will talk about the interactions between galaxies and how they influence their dynamics and morphology. The presentation will focus on recent results of simulations following an interaction of two similar disky galaxies on unbound orbits. It turns out that the result of the interaction can be very different depending on the relative orientation of the galaxy's internal spin and its orbital angular momentum. In the case of aligned spins and a sufficiently strong interaction, it can result in the formation of a tidally induced bar. The scenario will be placed in the cosmological context using the Illustris simulations. Then, I will discuss in detail the properties of such bars and the so-called buckling instability that occurs in them, when the bar becomes distorted out of the disk plane. I will present different measures of asymmetry in the edge-on view as well as kinematic signatures of buckling. I will demonstrate that tidally induced bars offer a unique possibility to obtain insight into the nature of buckling instability.
2019-03-07 (Thursday)
room 1.01, Pasteura 5 at 12:15
Michał Artymowski (Ariel University, Israel)Swampland conjecture and f(R) theory
I will present a brief introduction to the swampland conjecture and I will show how it influences the general conditions on scalar theories in the early Universe. In principle, I will focus on the f(R) and Brans-Dicke theories of gravity, which may be expressed as scalar theories in the Einstein frame. I will show how the swampland conjecture limits the possibilities of inflation in f(R) I will also show how a scalaron field may provide an easy way out of swampland.
2019-02-28 (Thursday)
room 1.01, Pasteura 5 at 12:15
dr hab. Tomasz Pawłowski (CFT PAN)Emergent de Sitter epoch of the quantum Cosmos
By using the regularization techniques of Loop Quantum Gravity we reexamine the quantum nature of the Big Bang in the framework of Loop Quantum Cosmology. The studies of the dynamics of a simple isotropic quantum Universe lead to a qualitative modification to the 'traditional' LQC bounce paradigm. Quantum gravity effects still lead to a quantum bounce connecting deterministically large classical Universes. However, the evolution features a large epoch of de Sitter Universe, with emergent cosmological constant of Planckian order, smoothly transiting into a flat expanding Universe.
2019-01-24 (Thursday)
room 1.01, Pasteura 5 at 12:15
Zhong-zhi Xianyu (Harvard University)Cosmological Collider Phenomenology: the Standard Model and Beyond
2019-01-17 (Thursday)
room 1.01, Pasteura 5 at 12:15
Giovanni Grilli di Cortona (IFT UW)Hidden Valley phenomenology: from colliders to cosmology
2019-01-10 (Thursday)
room 1.01, Pasteura 5 at 12:15
Terry Pilkington (IFT UW)Constraining scalar multiplet extensions of the Standard Model
2018-12-20 (Thursday)
room 1.01, Pasteura 5 at 12:15
Michele Oliosi (YITP, Kyoto University)Two modified gravity theories with few degrees of freedom
2018-12-13 (Thursday)
room 1.01, Pasteura 5 at 12:15
Sho Iwamoto (University of Padova)MSSM in light of the muon g-2 anomaly and dark matter
2018-12-06 (Thursday)
room 1.01, Pasteura 5 at 12:15
Howard Haber (University of California, Santa Cruz)Symmetries and Mass Degeneracies in the Scalar Sector
In this talk, I explore some aspects of extended Higgs sectors that lead to exact mass degeneracies among some of the physical scalars. Natural scalar mass degeneracies are possible in the inert two Higgs doublet model (IDM). In the case of three doublets, I present an extension of the IDM and then generalize this model to obtain a scalar potential, first proposed by Ivanov and Silva (IS), with a CP4 symmetry that guarantees the existence of pairwise degenerate scalar states among the neutral and charged Higgs scalars. The symmetries of the model permit a term in the IS scalar potential with a complex coefficient that cannot be removed by any redefinition of the scalar fields within the class of Higgs bases (in which case, we say that no real Higgs basis exists and the conventional CP symmetry is absent). Moreover, I show that it is possible to physically distinguish between the existence or nonexistence of a real Higgs basis in the IS model despite the fact that no CP-violating observables exist in either case.