Thursday, April 3rd, 2025
Workshop: Amihay Hanany
Time: 9:30 AM - 10:30 AM
Location: SCGP 102
Title: TBD
Speaker: Amihay Hanany
Abstract: TBD
Title: TBD
Speaker: Amihay Hanany
Abstract: TBD
Workshop: Shlomo Razamat
Time: 11:00 AM - 12:00 PM
Location: SCGP 102
Title: Generalized lattices, conformal manifolds, and symmetries
Speaker: Shlomo Razamat
Title: Generalized lattices, conformal manifolds, and symmetries
Speaker: Shlomo Razamat
YITP Event: YITP Seminar Speaker: Eric Putney (Rutgers)
Time: 11:00 AM - 12:00 PM
Location: YITP Common Room 6-125
Title: Machine Learning for Galactic Dynamics - model-free analyses of Gaia: mapping the local potential, dust, and dark matter
Abstract: The massive Gaia survey coupled with novel techniques in machine learning has ushered in new era of astrometry - the study of the motions of stars - allowing particle physicists to study the influence of dark matter on stars in our galactic neighborhood. In particular, I am interested in using normalizing flows to accurately model the complex six-dimensional phase space of local stars, allowing us to solve the equilibrium collisionless Boltzmann equation in full generality. I will present a brief timeline of flow-based solutions to the Boltzmann equation, demonstrating its success in toy systems and the road to the analysis of the real Gaia DR3 six-dimensional dataset. Finally, I will present our map of the local gravitational potential, the local dark matter density, and the outlook for and challenges of this novel analysis.
Title: Machine Learning for Galactic Dynamics - model-free analyses of Gaia: mapping the local potential, dust, and dark matter
Abstract: The massive Gaia survey coupled with novel techniques in machine learning has ushered in new era of astrometry - the study of the motions of stars - allowing particle physicists to study the influence of dark matter on stars in our galactic neighborhood. In particular, I am interested in using normalizing flows to accurately model the complex six-dimensional phase space of local stars, allowing us to solve the equilibrium collisionless Boltzmann equation in full generality. I will present a brief timeline of flow-based solutions to the Boltzmann equation, demonstrating its success in toy systems and the road to the analysis of the real Gaia DR3 six-dimensional dataset. Finally, I will present our map of the local gravitational potential, the local dark matter density, and the outlook for and challenges of this novel analysis.
Physics Seminar: Csaba Csaki
Time: 2:00 PM - 3:00 PM
Location: 313
Title: Lessons from the Seiberg-Witten axion
Abstract: The photon-axion coupling is our main experimental tool for axion searches. Since it is generated by the anomaly, it is usually expected to be quantized and its magnitude to be well constrained. However some of these arguments seem to be invalidated by the presence of magnetic monopoles charged under the PQ symmetries. We try to clarify these issues by examining a toy example based on the SU(2) Seiberg-Witten theory where all of these ingredients appear automatically. We determine the effect of the magnetic monopole (or equivalently those of strongly coupled instantons) on the axion coupling and comment on the duality of the Maxwell equations for axion electrodynamics.
Title: Lessons from the Seiberg-Witten axion
Abstract: The photon-axion coupling is our main experimental tool for axion searches. Since it is generated by the anomaly, it is usually expected to be quantized and its magnitude to be well constrained. However some of these arguments seem to be invalidated by the presence of magnetic monopoles charged under the PQ symmetries. We try to clarify these issues by examining a toy example based on the SU(2) Seiberg-Witten theory where all of these ingredients appear automatically. We determine the effect of the magnetic monopole (or equivalently those of strongly coupled instantons) on the axion coupling and comment on the duality of the Maxwell equations for axion electrodynamics.
Math Event: Colloquium: Daniel Pomerleano - Cohomological splittings in algebraic and symplectic geometry
Time: 2:15 PM - 3:15 PM
Location:
Title: Cohomological splittings in algebraic and symplectic geometry
Speaker: Daniel Pomerleano [UMass Boston]
Abstract: In the 1980s, Atiyah, Bott, and Kirwan established fundamental results on the rational cohomology of a compact symplectic manifold X with a Hamiltonian action of a connected, compact group G. I will review these classical results and then discuss recent integral and even stable homotopical refinements, drawing on ideas from chromatic homotopy theory and Gromov-Witten theory. This talk is based on joint work with Shaoyun Bai, Guangbo Xu, and Constantin Teleman. View Details
Title: Cohomological splittings in algebraic and symplectic geometry
Speaker: Daniel Pomerleano [UMass Boston]
Abstract: In the 1980s, Atiyah, Bott, and Kirwan established fundamental results on the rational cohomology of a compact symplectic manifold X with a Hamiltonian action of a connected, compact group G. I will review these classical results and then discuss recent integral and even stable homotopical refinements, drawing on ideas from chromatic homotopy theory and Gromov-Witten theory. This talk is based on joint work with Shaoyun Bai, Guangbo Xu, and Constantin Teleman. View Details
Workshop: Dmytro Matvieievskyi
Time: 2:30 PM - 3:30 PM
Location: SCGP 102
Title: Hikita conjecture for Slodowy slices and nilpotent orbit covers
Speaker: Dmytro Matvieievskyi
Abstract: Let G and G^\vee be Langlands dual complex semisimple groups. Consider a nilpotent coadjoint orbit for G^\vee, and let X^\vee be the corresponding nilpotent Slodowy slice, In a joint work with Ivan Losev and Lucas Mason-Brown we suggested that the symplectic dual to X^'vee should be an affinization X of a certain G-equivariant cover of a nilpotent coadjoint G-orbit. The Hikita conjecture predicts an isomorphism between the cohomology of the symplectic resolution of X^\vee and the algebra of functions of the schematic fixed points of X with respect to the maximal Hamiltonian torus. In this talk I will explain why this conjecture fails as stated, and how we modify it to get a new statement that we expect to be true and can prove in some cases. The talk is based on a joint work with Do Kien Hoang and Vasily Krylov.
Title: Hikita conjecture for Slodowy slices and nilpotent orbit covers
Speaker: Dmytro Matvieievskyi
Abstract: Let G and G^\vee be Langlands dual complex semisimple groups. Consider a nilpotent coadjoint orbit for G^\vee, and let X^\vee be the corresponding nilpotent Slodowy slice, In a joint work with Ivan Losev and Lucas Mason-Brown we suggested that the symplectic dual to X^'vee should be an affinization X of a certain G-equivariant cover of a nilpotent coadjoint G-orbit. The Hikita conjecture predicts an isomorphism between the cohomology of the symplectic resolution of X^\vee and the algebra of functions of the schematic fixed points of X with respect to the maximal Hamiltonian torus. In this talk I will explain why this conjecture fails as stated, and how we modify it to get a new statement that we expect to be true and can prove in some cases. The talk is based on a joint work with Do Kien Hoang and Vasily Krylov.
Workshop: Alexander Braverman
Time: 4:00 PM - 5:00 PM
Location: SCGP 102
Title: Koszul duality in Relative Langlands duality/S-duality.
Speaker: Alexander Braverman
Abstract: Ben-Zvi, Sakellaridis and Venkatesh conjectured that X is a smooth affine spherical variety over a reductive group G (the definition will be recalled at the talk) then to that one can explicitly attached certain Poisson variety Y^{\vee} over the Langlands dual group G^{\vee} of G (over it is equal to cotangent bundle of some (also spherical) G^{\vee}-variety X^{\vee}), so that the (derived) category of G[[t]]-equivariant sheaves on X((t)) which are also equivariant with respect to the loop rotation is equivalent to the category of G^{\vee} over the quantization of Y (viewed as a dg-algebra with certain grading). This can be thought of some special case of S-duality for boundary conditions in 4d gauge theory. This has been checked in many case (some examples will be discussed at the talk). I will talk about a conjecture of Finkelberg, Ginzburg and Travkin which says that the category of B-equivariant sheaves on X should be Koszul dual to a close relative of the category B^{\vee}-equivariant modules over the quantization of Y^{\vee} (more precisely, the word "equivariant" must be replaced with "monodromic with unipotent monodromy"). In the case when X=G considered as a space with GxG-action, one recovers a well-known work of Beilinson, Ginzburg and Soergel. The purpose of the talk will be: 1) Give a review of cases when the Ben-Zvi-Sakellaridis-Venktatesh conjecture is known 2) Explain a framework for proving this conjecture in a slightly weaker form (instead of Koszul duality we shall prove an equivalence of the corresponding Z_2-graded categories). The latter part is a joint work with M.Finkelberg and R.Travkin.
Title: Koszul duality in Relative Langlands duality/S-duality.
Speaker: Alexander Braverman
Abstract: Ben-Zvi, Sakellaridis and Venkatesh conjectured that X is a smooth affine spherical variety over a reductive group G (the definition will be recalled at the talk) then to that one can explicitly attached certain Poisson variety Y^{\vee} over the Langlands dual group G^{\vee} of G (over it is equal to cotangent bundle of some (also spherical) G^{\vee}-variety X^{\vee}), so that the (derived) category of G[[t]]-equivariant sheaves on X((t)) which are also equivariant with respect to the loop rotation is equivalent to the category of G^{\vee} over the quantization of Y (viewed as a dg-algebra with certain grading). This can be thought of some special case of S-duality for boundary conditions in 4d gauge theory. This has been checked in many case (some examples will be discussed at the talk). I will talk about a conjecture of Finkelberg, Ginzburg and Travkin which says that the category of B-equivariant sheaves on X should be Koszul dual to a close relative of the category B^{\vee}-equivariant modules over the quantization of Y^{\vee} (more precisely, the word "equivariant" must be replaced with "monodromic with unipotent monodromy"). In the case when X=G considered as a space with GxG-action, one recovers a well-known work of Beilinson, Ginzburg and Soergel. The purpose of the talk will be: 1) Give a review of cases when the Ben-Zvi-Sakellaridis-Venktatesh conjecture is known 2) Explain a framework for proving this conjecture in a slightly weaker form (instead of Koszul duality we shall prove an equivalence of the corresponding Z_2-graded categories). The latter part is a joint work with M.Finkelberg and R.Travkin.