Identifier,"Start Date / Time","End Date / Time",Title,Subtitle,Type,Description,Permalink,"Building Name",Room,"Location Name",Cost,Tags,Sponsors
119253-21842487,"2024-03-13 13:00:00","2024-03-13 14:00:00","HET Brown Bag Seminar | Recent progress on Coon amplitudes: the N-point amplitude and an exact field-theory limit","Nick Geiser (UM)","Lecture / Discussion","In the last two years, Coon amplitudes have received a burst of renewed interest in the context of the modern S-matrix bootstrap program. The four-point Coon amplitude was first discovered in 1969 by D.D. Coon and is a deformation of string theory’s famous Veneziano amplitude with a free deformation parameter q. At q = 1, Coon amplitudes become tree-level open string amplitudes. Recently, several groups have studied the low-energy expansion of Coon amplitudes, the unitarity properties of Coon amplitudes, various extensions and generalizations of Coon amplitudes, and possible physical models realizing the Coon spectrum. In this seminar, I will survey these recent developments along with some new results on N-point Coon amplitudes. By studying the N-point Coon amplitude, we will discover a particular limit which reproduces the tree-level amplitudes of a particular field theory with an infinite set of non-derivative single-trace interaction terms. This correspondence is the first definitive realization of the Coon amplitude (in any limit) from a field theory described by an explicit Lagrangian.",https://events.umich.edu/event/119253,"Randall Laboratory",3481,"Randall Laboratory",,"Brown Bag Seminar","Leinweber Center for Theoretical Physics
Department of Physics
HET Brown Bag Series
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics Brown Bag Seminars"
119252-21842486,"2024-03-20 13:00:00","2024-03-20 14:00:00","HET Brown Bag Seminar | Dynamical equilibration of dark matter and baryon energy densities","Dawid Brzeminski (U Maryland)","Lecture / Discussion","The near equality of the dark matter and baryon energy densities is a remarkable coincidence, especially when one realizes that the baryon mass is exponentially sensitive to UV parameters in the form of dimensional transmutations. We explore a new dynamical mechanism, where in the presence of an arbitrary number density of baryons and dark matter, a scalar adjusts the masses of dark matter and baryons until the two energy densities are comparable. In this manner, the coincidence is explained regardless of the microscopic identity of dark matter and how it was produced. This new scalar causes a variety of experimental effects such as a new force and a (dark) matter density dependent proton mass.",https://events.umich.edu/event/119252,"Randall Laboratory",3481,"Randall Laboratory",,"Brown Bag Seminar","Leinweber Center for Theoretical Physics
Department of Physics
HET Brown Bag Series
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics Brown Bag Seminars"
117229-21838852,"2024-04-03 13:00:00","2024-04-03 14:00:00","HET Brown Bag Seminar | Cryptographic Censorship","Evita Verheijden (Harvard)","Lecture / Discussion","The classical formulation of the weak cosmic censorship conjecture (WCCC) – the statement that singularities resulting from gravitational collapse are generically hidden behind event horizons – is most probably false. However, I will argue that there is compelling evidence that some version of it should be true in quantum gravity. Working towards a quantum gravitational formulation of the WCCC, I will prove “Cryptographic Censorship”, a theorem that provides a general condition for the formation of event horizons in AdS/CFT: sufficiently (pseudo)random boundary dynamics. I will also provide a classification of sizes of singularities, and show that “large”, “classical” singularities – the ones that the WCCC should rule out – are compatible with sufficiently (pseudo)random dynamics. Thus, if such singularities are indeed described by (pseudo)random dynamics, then they cannot exist in the absence of event horizons.",https://events.umich.edu/event/117229,"Randall Laboratory",3481,"Randall Laboratory",,"Brown Bag Seminar","Leinweber Center for Theoretical Physics
Department of Physics
HET Brown Bag Series
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics Brown Bag Seminars"
117230-21838853,"2024-04-10 13:00:00","2024-04-10 14:00:00","HET Brown Bag Seminar | Physics Potential at a future Muon Collider","Cari Cesarotti (MIT)","Lecture / Discussion","A clear outcome of Snowmass 2021 and now the US P5 report was the community support for R&D towards a future muon collider. In this talk we will discuss the general physics program that becomes available to the community during the construction and completion of the future collider. We will review not only the main challenges and advantages of such a collider compared to other possibilities, but also the projected reach of several specific models. Additionally, we consider the physics possibilities at the necessary demonstrator facilities along the way. For example, a beam dump would be an economical and effective way to increase the discovery potential of the collider complex in a complementary regime.",https://events.umich.edu/event/117230,"Randall Laboratory",3481,"Randall Laboratory",,"Brown Bag Seminar","Leinweber Center for Theoretical Physics
Department of Physics
HET Brown Bag Series
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics Brown Bag Seminars"
117231-21838854,"2024-04-17 13:00:00","2024-04-17 14:00:00","HET Brown Bag Seminar | Quantum Many-body Bootstrap","Yuan Xin (Carnegie Mellon)","Lecture / Discussion","Determining the long-range phase of matter from its microscopic description has long been one of the central topics in physics. Simple microscopic systems often become strongly coupled at long range where we usually rely on clever approximations. Bootstrap is an alternative approach that uses positivity and equations of motion to make predictions in quantum many-body systems without making approximations. In this talk, I will show my recent work on using bootstrap to compute the ground state energy, local observables and gaps of a quantum many-body system in the thermodynamic limit with rigorous error bars.",https://events.umich.edu/event/117231,"Randall Laboratory",3481,"Randall Laboratory",,"Brown Bag Seminar","Leinweber Center for Theoretical Physics
Department of Physics
HET Brown Bag Series
Leinweber Center for Theoretical Physics Seminars
Leinweber Center for Theoretical Physics Brown Bag Seminars"