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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240415T090000
DTEND;TZID=America/New_York:20240524T170000
DTSTAMP:20260503T092634
CREATED:20230904T173915Z
LAST-MODIFIED:20240624T181936Z
UID:10000003-1713171600-1716570000@cmsa.fas.harvard.edu
SUMMARY:Program on Mathematical Aspects of Scattering Amplitudes
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Program \nDates: April 15 – May 24\, 2024 \nLocation: Harvard CMSA\, 20 Garden Street\, Cambridge\, MA 02138 \nThis program will bring together and foster interaction between theoretical physicists and mathematicians working on various topics connected to recent developments in our understanding of scattering amplitudes in quantum field theory. The field has advanced considerably since 2019 when the CMSA hosted the program “Spacetime and Quantum Mechanics\, Total Positivity and Motives.” Recent developments have primed this area for further significant advances\, which will be facilitated by bringing together many of the relevant experts for intensive discussion and collaboration. \nThe program will feature a weekly seminar series. \nTuesday\, April 16\, 2024\n4:15 pm\nSabrina Pasterski\, Perimeter Institute\nTitle: Radiation in Holography \n[Physics Talk]\nWednesday\, April 17\, 2024\n4:30 pm –  Cruft 309\nAna-Maria Raclariu\, King’s College London \nThursday\, April 18\, 2024\n4:15 pm\nLionel Mason\, University of Oxford\nTitle: Hidden symmetries of SD Poincare Einstein metrics in split signature \n[Physics Talk]\nTuesday\, April 23\, 2024\n4:30 pm – Jefferson 256\nJuan Maldacena\, Institute for Advanced Study \nThursday\, April 25\, 2024\n4:15 pm\nTomasz Taylor\, Northeastern University\nTitle: Progress in Yang-Mills-Liouville Theory \n[CMSA Colloquium]\nMonday\, April 29\, 2024\n4:30 – 5:30 pm\nLance Dixon\, Stanford\nTitle: The DNA of Particle Scattering \nTuesday\, April 30\, 2024\n9:00 am- Jefferson 453\nNima Arkani-Hamed\, IAS\nTitle: Surfaceology and the Real World Part 1 \n1:00 pm – Jefferson 453\nNima Arkani-Hamed\, IAS\nTitle: Surfaceology and the Real World Part 2 \n4:00 pm – Jefferson 453\nNima Arkani-Hamed\, IAS\nTitle: Surfaceology and the Real World Part 3 \nWednesday\, May 1\, 2024\n11:00 am – Science Center 507\nJaroslav Trnka\, UC Davis\nTitle: Loops of loops expansion in the Amplituhedron \n3:00 pm\nYu-tin Huang\, National Taiwan University\nTitle: Loop in trees: Chambers in amplitudes and correlation functions \n4:00 pm\nLivia Ferro\, University of Hertfordshire\nTitle: Scattering Amplitudes from Null-cone Geometry \n5:00 pm\nStephan Stieberger\, Max Planck Institute\nTitle: One-loop Double Copy Relation in String Theory and Twisted (Co)homology \nThursday\, May 2\, 2024\n11:00 am – Science Center 310\nDaniil Rudenko\, Chicago\nTitle: Introduction to Cluster Polylogarithms \nFriday\, May 3\, 2024\n11:00 am\nAndrew McLeod\, Edinburgh\nTitle: Genealogical Constraints on Feynman Integrals \nTuesday\, May 7\, 2024\n3:00 pm\nJacob Bourjaily\, Penn State\nTitle: The Algebraic and Transcendental Structure of Perturbative QFT \nWednesday\, May 8\, 2024\n3:00 pm\nRuth Britto\, Trinity\nTitle: Cuts and Symbols \nTuesday\, May 14\, 2024\n3:00 pm\nJames Drummond\, University of Southampton\nTitle: Multiple light-like Wilson loops in N=4 super Yang-Mills theory \nWednesday\, May 15\, 2024\n3:00 pm\nMatteo Parisi\, Harvard CMSA\nTitle: The amplituhedron and cluster algebras \nTuesday\, May 21\, 2024\n11:00 am\nMichael Borinsky\, ETH Zurich\nTitle: On the Euler characteristic of the commutative graph complex and the top-weight cohomology of the moduli space of curves \nWednesday\, May 22\, 2024\n11:00 am\nChaim Even-Zohar\, Technion\nTitle: Amplituhedron tiles and twistor polynomials \n  \nOrganizers: \n\nNima Arkani-Hamed (Institute for Advanced Study)\nMarcus Spradlin (Brown University)\nAndrew Strominger (Harvard University)\nAnastasia Volovich (Brown University)\nLauren Williams (Harvard University)\n\nParticipants: \n\n\nMichael Borinsky\, ETH Zurich\nJacob Bourjaily\, Pennsylvania State University\nRuth Britto\, Trinity College\nLance Dixon\, Stanford Linear Accelerator Center\nJames Drummond\, University of Southampton\nChaim Even-Zohar\, Technion\nLivia Ferro\, University of Hertfordshire\nCarolina Figueiredo\, Princeton University\nHadleigh Frost\, Oxford University\nBruno Gimenez\, University of Southampton\nOmer Gurdogan\, University of Southampton\nXuhua He\, Chinese University of Hong Kong\nPaul Heslop\, Durham University\nYu-Tin Huang\, National Taiwan University\nDani Kaufman\, University of Copenhagen\nJianrong Li\, University of Vienna\nTomasz Lukowski\, University of Hertfordshire\nYelena Mandelshtam\, University of California\, Berkeley\nLionel Mason\, University of Oxford\nAndrew McLeod\, University of Edinburgh\nNatalie Paquette\, University of Washington\nMatteo Parisi\, Harvard University\nSabrina Pasterski\, Perimeter Institute\nDmitri Pavlov\, Max Planck Institute for Mathematics in the Sciences\, Leipzig\nLizzie Pratt\, University of California\, Berkeley\nClaudia Rella\, University of Geneva\nDaniil Rudenko\, University of Chicago\nGiulio Salvatori\, Max Planck Institute for Physics\nMelissa Sherman-Bennett\, Massachusetts Institute of Technology\nJonah Stalknecht\, University of Hertfordshire\nStephan Stieberger\, Max Planck Institute\nTomasz Taylor\, Northeastern University\nRan Tessler\, Weizmann Institute of Science\nHugh Thomas\, Université du Québec à Montréal\nJaroslav Trnka\, University of California\, Davis\nCristian Vergu\, Pennsylvania State University
URL:https://cmsa.fas.harvard.edu/event/scattering-amplitudes/
LOCATION:CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Event,Programs
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Page-88-from-2310.17727_crop.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240416T110000
DTEND;TZID=America/New_York:20240416T120000
DTSTAMP:20260503T092634
CREATED:20240409T163938Z
LAST-MODIFIED:20240502T195940Z
UID:10000832-1713265200-1713268800@cmsa.fas.harvard.edu
SUMMARY:New Well-Posed Boundary Conditions for Semi-Classical Euclidean Gravity
DESCRIPTION:General Relativity Seminar \nSpeaker: Xiaoyi Liu\, UCSB \nTitle: New Well-Posed Boundary Conditions for Semi-Classical Euclidean Gravity \nAbstract: We consider four-dimensional Euclidean gravity in a finite cavity.  We point out that there exists a one-parameter family of boundary conditions\, parameterized by a real constant\, where a suitably Weyl-rescaled boundary metric is fixed\, and all give a well-posed elliptic system\, as opposed to the Dirichlet boundary condition. Focussing on static Euclidean solutions\, we derive a thermodynamic first law. Restricting to a spherical spatial boundary\, the infillings are flat space or the Schwarzschild solution and have similar thermodynamics to the Dirichlet case. We study the stability behavior of several geometries under these boundary conditions in both Euclidean and Lorentzian signatures and find two puzzles.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar_41624/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-04.16.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240416T123000
DTEND;TZID=America/New_York:20240416T133000
DTSTAMP:20260503T092634
CREATED:20240206T175201Z
LAST-MODIFIED:20240425T205435Z
UID:10000849-1713270600-1713274200@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar 4/16/2024
DESCRIPTION:CMSA Q and A Seminar\n\nSpeaker: Cengiz Pehlevan\, Harvard\n\nQuestion: What is feature learning?
URL:https://cmsa.fas.harvard.edu/event/cmsaqa-41624/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240416T161500
DTEND;TZID=America/New_York:20240416T171500
DTSTAMP:20260503T092634
CREATED:20240415T173854Z
LAST-MODIFIED:20240415T174657Z
UID:10003362-1713284100-1713287700@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Sabrina Pasterski\, Perimeter Institute \nTitle: Radiation in Holography
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_41624/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240418T101500
DTEND;TZID=America/New_York:20240418T113000
DTSTAMP:20260503T092635
CREATED:20240415T133328Z
LAST-MODIFIED:20240813T153315Z
UID:10000887-1713435300-1713439800@cmsa.fas.harvard.edu
SUMMARY:Geometric local systems on very general curves
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Aaron Landesman\, MIT \nTitle: Geometric local systems on very general curves \nAbstract: What is the smallest genus h of a non-isotrivial curve over the generic genus g curve? In joint work with Daniel Litt\, we show h is more than $\sqrt{g}$ by proving amore general result about variations of Hodge structure on sufficiently general curves. As a consequence\, we show that local systems on a sufficiently general curve of geometric origin are not Zariski dense in the character variety parameterizing such local systems. This gives counterexamples to conjectures of Esnault-Kerz and Budur-Wang.
URL:https://cmsa.fas.harvard.edu/event/agst-41824/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Algebraic-Geometry-in-String-Theory-04.18.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240419T100000
DTEND;TZID=America/New_York:20240419T113000
DTSTAMP:20260503T092635
CREATED:20240319T134714Z
LAST-MODIFIED:20240412T153042Z
UID:10001515-1713520800-1713526200@cmsa.fas.harvard.edu
SUMMARY:Fusion Rule Measurement in a Topological Qubit
DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Chetan Nayak\, Microsoft and UCSB \nTitle: Fusion Rule Measurement in a Topological Qubit
URL:https://cmsa.fas.harvard.edu/event/qm-41924/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Matter
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QMMP-04.19.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240419T120000
DTEND;TZID=America/New_York:20240419T130000
DTSTAMP:20260503T092635
CREATED:20240305T155850Z
LAST-MODIFIED:20240418T194607Z
UID:10000689-1713528000-1713531600@cmsa.fas.harvard.edu
SUMMARY:Member Seminar
DESCRIPTION:CMSA Member Seminar \nSpeaker: Sunghyuk Park\, Harvard CMSA \nTitle: 3D quantum trace map \nAbstract: I will speak about my recent work (joint with Sam Panitch) constructing the 3d quantum trace map\, a homomorphism from the Kauffman bracket skein module of an ideally triangulated 3-manifold to its (square root) quantum gluing module\, thereby giving a precise relationship between the two quantizations of the character variety of ideally triangulated 3-manifolds. Our construction is based on the study of stated skein modules and their behavior under splitting\, especially into face suspensions. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-41924/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Member-Seminar-04.19.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240423T100000
DTEND;TZID=America/New_York:20240423T110000
DTSTAMP:20260503T092635
CREATED:20240415T162430Z
LAST-MODIFIED:20240422T154105Z
UID:10000833-1713866400-1713870000@cmsa.fas.harvard.edu
SUMMARY:Quantum Energy Inequalities
DESCRIPTION:General Relativity Seminar \nSpeaker: Chris Fewster\, York University \nTitle: Quantum Energy Inequalities \nAbstract: Many theorems of mathematical relativity\, including singularity and positive mass theorems\, include the classical energy conditions among their hypotheses. However\, matter described by quantum field theory can violate the classical energy conditions and indeed there is no lower bound to the energy density at a given point as the quantum state is varied. Do the classical theorems apply to quantised matter? \nIn this talk I discuss Quantum Energy Inequalities\, lower bounds on averages of the energy density along timelike curves or over spacetime regions\, that have been proved in QFT and are the remnants of the classical energy conditions after quantisation. I will also discuss some of their consequences.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar_42324/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240423T123000
DTEND;TZID=America/New_York:20240423T133000
DTSTAMP:20260503T092635
CREATED:20240206T175344Z
LAST-MODIFIED:20240425T205425Z
UID:10000850-1713875400-1713879000@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar 4/23/2024
DESCRIPTION:CMSA Q and A Seminar\n\nSpeaker: Melanie Weber\, Harvard\n\nQuestion: What is the Ricci curvature of a graph?
URL:https://cmsa.fas.harvard.edu/event/cmsaqa-42324/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240425T103000
DTEND;TZID=America/New_York:20240425T113000
DTSTAMP:20260503T092635
CREATED:20240416T133525Z
LAST-MODIFIED:20240422T185259Z
UID:10000888-1714041000-1714044600@cmsa.fas.harvard.edu
SUMMARY:The logarithmic double ramification locus
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Alessandro Chiodo\, IMJ-Paris Rive Gauche (Jussieu) \nTitle: The logarithmic double ramification locus \nAbstract: Given a family of smooth curves C -> S with a line bundle L on C\, it is natural to study the locus of points x in S where L_x is trivial on C_x. When the family is stable\, the definition can be extended\, not directly on the base scheme S\, but more naturally on a (logarithmic) blow-up S’ of S. The problem is in many ways analogue to the problem of defining a Néron model on the moduli space of stable curves (instead of a DVR). Over the past years\, David Holmes and his collaborators pioneered a new approach on a logarithmic modification of the entire moduli space of curves. In this talk\, we determine this logarithmic double ramification cycle and several variants and alternative presentations of it (work in collaboration with David Holmes).
URL:https://cmsa.fas.harvard.edu/event/agst-42524/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-04.25.2024.docx-2.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240425T161500
DTEND;TZID=America/New_York:20240425T171500
DTSTAMP:20260503T092635
CREATED:20240415T174444Z
LAST-MODIFIED:20240415T174731Z
UID:10003363-1714061700-1714065300@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Tomasz Taylor\, Northeastern University \nTitle: Progress in Yang-Mills-Liouville Theory
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_42524/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240426T103000
DTEND;TZID=America/New_York:20240426T120000
DTSTAMP:20260503T092635
CREATED:20240416T135637Z
LAST-MODIFIED:20240418T195101Z
UID:10001516-1714127400-1714132800@cmsa.fas.harvard.edu
SUMMARY:What Observables are Safe to Calculate?
DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Jesse Thaler\, MIT \nTitle: What Observables are Safe to Calculate? \nAbstract: In collider physics\, perturbative quantum field theory is the workhorse framework for computing theoretical predictions to compare to experimental measurements. An observable is called “safe” if its cross section can be predicted order-by-order in perturbation theory with controlled non-perturbative corrections. In this talk\, I show that naive definitions of “safety” are inadequate to determine which observable are perturbatively calculable. I then argue for a more refined definition of safety based on principles from optimal transport theory.
URL:https://cmsa.fas.harvard.edu/event/qm_42624_2/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Matter
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QMMP-04.26.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240426T120000
DTEND;TZID=America/New_York:20240426T130000
DTSTAMP:20260503T092635
CREATED:20240305T160053Z
LAST-MODIFIED:20240416T185829Z
UID:10000691-1714132800-1714136400@cmsa.fas.harvard.edu
SUMMARY:Member Seminar
DESCRIPTION:CMSA Member Seminar \nSpeaker: Matteo Parisi\, Harvard CMSA
URL:https://cmsa.fas.harvard.edu/event/member-seminar-42624/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240429T090000
DTEND;TZID=America/New_York:20240503T170000
DTSTAMP:20260503T092635
CREATED:20240105T071054Z
LAST-MODIFIED:20240624T182013Z
UID:10001119-1714381200-1714755600@cmsa.fas.harvard.edu
SUMMARY:Workshop on Global Categorical Symmetries
DESCRIPTION:The CMSA will be hosting a Workshop on Global Categorical Symmetries from April 29–May 3\, 2024. \nParticipation in the workshop is by invitation. \nThe workshop will hold three Symmetry Colloquia open to the community on Thursday\, May 2\, 2024. \nLocation:  Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nTime: 2:00 – 2:50 pm \nSpeaker: Clay Còrdova\, University of Chicago \nTitle: Particle-Soliton Degeneracies from Spontaneously Broken Non-Invertible Symmetry \nAbstract: We study non-invertible topological symmetry operators in massive quantum field theories in (1+1) dimensions. In phases where this symmetry is spontaneously broken we show that the particle spectrum often has degeneracies dictated by the non-invertible symmetry and we deduce a procedure to determine the allowed multiplets. These degeneracies are robust predictions and do not require integrability or other special features of renormalization group flows. We exhibit these conclusions in examples where the spectrum is known\, recovering soliton and particle degeneracies. For instance\, the Tricritical Ising model deformed by the subleading Z2 odd operator flows to a gapped phase with two degenerate vacua. This flow enjoys a Fibonacci fusion category symmetry which implies a threefold degeneracy of its particle states\, relating the mass of solitons interpolating between vacua and particles supported in a single vacuum. \n  \nLocation:  Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nTime: 3:00 – 3:50 pm \nSpeaker: Thomas Dumitrescu\, UCLA \nTitle: Symmetries\, Invertible Field Theories\, and Gauge Theory Phases \nAbstract: I will start with a brief overview of gauge theory phases in 3+1 dimensions through the lens of higher symmetries — in particular the realization of 1-form symmetries acting on loop order parameters. I will then review recent progress in refining this characterization using invertible field theories\, or equivalently symmetry protected topological phases (SPTs). This refinement leads to new results in gauge theories with fundamental matter\, such as quantum chromodynamics (QCD)\, which do not possess 1-form symmetries. I will explain why these theories must sometimes undergo a phase transition between their confining and Higgs regimes\, despite the fact that classic results and standard lore say they should be continuously connected. \n  \nLocation:  Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nTime: 4:30 – 5:20 pm \nSpeaker: Theo Johnson-Freyd\, Dalhousie University and Perimeter Institute \nTitle: The Universal Target Category \nAbstract: Hilbert’s Nullstellensatz says that the complex numbers C satisfy a universal property among all R-algebras: every not-too-large nonzero commutative R-algebra maps to C. Deligne proved a similar statement in categorical dimension 1: every not-too-large symmetric monoidal category over R maps to the category sVec of super vector spaces. In other words\, sVec (and not Vec!) is “algebraically closed”. These statements help explain why quantum field theory requires imaginary numbers and fermions. I will describe the universal symmetric monoidal higher category that extends the sequence C\, sVec\, …. This is joint work in progress with David Reutter\, and builds on closely-related work by GCS collaborators Freed\, Scheimbauer\, and Teleman and Schlank et al. \n  \nOrganizers:\nDan Freed (Harvard CMSA & Math)\nConstantin Teleman  (UC Berkeley) \nThis event is co-sponsored by the Simons Foundation. 
URL:https://cmsa.fas.harvard.edu/event/globalcomputing24/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Workshop
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Symmetry-Lectures-poster-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240429T163000
DTEND;TZID=America/New_York:20240429T173000
DTSTAMP:20260503T092635
CREATED:20240207T190153Z
LAST-MODIFIED:20240424T142108Z
UID:10000818-1714408200-1714411800@cmsa.fas.harvard.edu
SUMMARY:The DNA of Particle Scattering
DESCRIPTION:Colloquium \nSpeaker: Lance Dixon (SLAC\, Stanford University) \nTitle: The DNA of Particle Scattering \nAbstract: At the Large Hadron Collider\, the copious scattering of quarks and gluons in quantum chromodynamics (QCD) produces Higgs bosons and many backgrounds to searches for new physics.  At short distances\, scattering in QCD can be evaluated in perturbation theory and leads to highly intricate\, multivariate mathematical functions such as generalized polylogarithms.  To gain further insight\, one can study a cousin of QCD called planar N=4 super-Yang-Mills theory.  Some processes in this theory can be computed to eighth order in perturbation theory\, versus second or third order in QCD.  The computation and analysis of these results rely on a Hopf algebra coaction on polylogarithms.  Its maximal iteration is called the ‘symbol’\, which serves as a ‘genetic code’ for amplitudes.  The symbol is a linear combination of words\, sequences of letters analogous to sequences of DNA base pairs.  Understanding the alphabet\, and then reading the code\, exposes the physics and mathematics of quantum scattering\, including bizarre new symmetries.  For example\, the two scattering amplitudes that are known to the highest orders in perturbation theory (8 loops) are related to each other by an ‘antipodal duality’\, which involves reading the code backwards as well as forwards. A third scattering amplitude\, which contains the other two as limits\, has an antipodal self-duality which ‘explains’ the other duality.  However\, we still don’t know ‘who ordered’ this property\, or what it really means. \n 
URL:https://cmsa.fas.harvard.edu/event/colloquium-42924/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-04.29.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240430T090000
DTEND;TZID=America/New_York:20240430T100000
DTSTAMP:20260503T092635
CREATED:20240415T175057Z
LAST-MODIFIED:20240430T133949Z
UID:10003365-1714467600-1714471200@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Nima Arkani-Hamed\, IAS \nTitle: Surfaceology and the Real World Part 1 \n(Note change of venue to Jefferson 453)
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_430243/
LOCATION:Jefferson 453\, 17 Oxford St\, Cambridge\, MA 02138\, MA
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240430T123000
DTEND;TZID=America/New_York:20240430T133000
DTSTAMP:20260503T092635
CREATED:20240129T171712Z
LAST-MODIFIED:20240212T155347Z
UID:10000851-1714480200-1714483800@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar 4/30/2024
DESCRIPTION:Speaker: Lakshminarayanan Mahadevan\n\nQuestion: What is morphogenesis? (Morphogenesis: geometry and biology)
URL:https://cmsa.fas.harvard.edu/event/cmsaqa-43024/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240430T130000
DTEND;TZID=America/New_York:20240430T140000
DTSTAMP:20260503T092635
CREATED:20240430T133851Z
LAST-MODIFIED:20240430T133851Z
UID:10003383-1714482000-1714485600@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Nima Arkani-Hamed\, IAS \nTitle: Surfaceology and the Real World Part 2 \n(Note change of venue to Jefferson 453)
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_43024_nah2/
LOCATION:Jefferson 453\, 17 Oxford St\, Cambridge\, MA 02138\, MA
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240430T160000
DTEND;TZID=America/New_York:20240430T170000
DTSTAMP:20260503T092635
CREATED:20240430T200741Z
LAST-MODIFIED:20240430T200741Z
UID:10003384-1714492800-1714496400@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Nima Arkani-Hamed\, IAS \nTitle: Surfaceology and the Real World Part 3 \n(Note change of venue to Jefferson 453)
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_43024_nah3/
LOCATION:Jefferson 453\, 17 Oxford St\, Cambridge\, MA 02138\, MA
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240501T110000
DTEND;TZID=America/New_York:20240501T120000
DTSTAMP:20260503T092635
CREATED:20240423T135245Z
LAST-MODIFIED:20240430T200942Z
UID:10003379-1714561200-1714564800@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Jaroslav Trnka\, University of California\, Davis \nTitle: Loops of loops expansion in the Amplituhedron
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_5124_trnka/
LOCATION:Science Center 507\, 1 Oxford Street\, Cambridge\, 02138
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240501T150000
DTEND;TZID=America/New_York:20240501T160000
DTSTAMP:20260503T092635
CREATED:20240415T175837Z
LAST-MODIFIED:20240429T134856Z
UID:10003366-1714575600-1714579200@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Yu-tin Huang\, National Taiwan University \nTitle: Loop in trees: Chambers in amplitudes and correlation functions
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_5124/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240501T160000
DTEND;TZID=America/New_York:20240501T170000
DTSTAMP:20260503T092635
CREATED:20240415T182314Z
LAST-MODIFIED:20240422T142214Z
UID:10003370-1714579200-1714582800@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Livia Ferro\, University of Hertfordshire \nTitle: Scattering Amplitudes from Null-cone Geometry
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_51242/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240501T170000
DTEND;TZID=America/New_York:20240501T180000
DTSTAMP:20260503T092635
CREATED:20240423T135511Z
LAST-MODIFIED:20240423T135511Z
UID:10003380-1714582800-1714586400@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Stephan Stieberger\, Max Planck Institute \nTitle: One-loop Double Copy Relation in String Theory and Twisted (Co)homology
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_51243/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240502T110000
DTEND;TZID=America/New_York:20240502T120000
DTSTAMP:20260503T092635
CREATED:20240415T174619Z
LAST-MODIFIED:20240502T144153Z
UID:10003364-1714647600-1714651200@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Daniil Rudenko\, U Chicago \nTitle: Introduction to Cluster Polylogarithms \nLocation: Harvard Science Center 310
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_5224dr/
LOCATION:Harvard Science Center\, 1 Oxford Street\, Cambridge\, MA\, 02138
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240502T133000
DTEND;TZID=America/New_York:20240502T143000
DTSTAMP:20260503T092635
CREATED:20240416T181909Z
LAST-MODIFIED:20240430T131929Z
UID:10003376-1714656600-1714660200@cmsa.fas.harvard.edu
SUMMARY:Non-dispersive one-way signal amplification in sonic metamaterials
DESCRIPTION:Active Matter Seminar \nSpeaker: Jayson Paulose\, University of Oregon \nTitle: Control of parametric amplification in space-time modulated mechanical metamaterials \nAbstract: Active mechanical metamaterials harbor acoustic signal processing functionalities that are impossible to achieve in passive structures. Amplifying an elastic wave as it passes through the material is a prominent example\, with potential applications in acoustic signal processing and loss mitigation. The fundamental mechanism for signal amplification of this kind is the parametric amplifier–an oscillator whose stiffness is periodically modulated in time\, which can inject energy into mechanical oscillations. Typically\, parametric amplification occurs at distinct modulation frequencies that are trivially related to the resonance modes of the unmodulated system\, which restricts its utility for amplifying signals with complex spatial or spectral structure. In this talk\, I’ll show how spatial variation of the modulation phase in parametric oscillator networks enables amplification phenomena that are far richer than those achievable by uncoupled and uncoordinated parametric amplifiers. Examples include turning off parametric resonances for particular vibrational modes in small assemblies [1]\, and achieving nonreciprocal broadband amplification in periodic arrays [2]. The existence of parametric resonances is tied to the internal symmetries inherent to mechanical systems as well as the symmetries obeyed by the parametric variation in space and time\, through an exact theoretical framework that augments the standard Floquet analysis of space-time modulated systems. \n  \n[1] Melkani and Paulose\, arXiv:2310.08734 \n[2] Kruss and Paulose\, PRApplied17\, 024020 (2022)
URL:https://cmsa.fas.harvard.edu/event/active-matter-5224/
LOCATION:Jefferson 256\, 17 Oxford Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Active Matter Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Active-Matter-Seminar-05.02.2024-2.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240502T140000
DTEND;TZID=America/New_York:20240502T145000
DTSTAMP:20260503T092635
CREATED:20240415T162849Z
LAST-MODIFIED:20240417T181513Z
UID:10003356-1714658400-1714661400@cmsa.fas.harvard.edu
SUMMARY:Symmetry Colloquia - Global Categorical Symmetries
DESCRIPTION:Symmetry Colloquia – Global Categorical Symmetries \nMay 2\, 2024 \nLocation: Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nSpeaker: Clay Còrdova\, University of Chicago \nTitle:  Particle-Soliton Degeneracies from Spontaneously Broken Non-Invertible Symmetry \nAbstract: We study non-invertible topological symmetry operators in massive quantum field theories in (1+1) dimensions. In phases where this symmetry is spontaneously broken we show that the particle spectrum often has degeneracies dictated by the non-invertible symmetry and we deduce a procedure to determine the allowed multiplets. These degeneracies are robust predictions and do not require integrability or other special features of renormalization group flows. We exhibit these conclusions in examples where the spectrum is known\, recovering soliton and particle degeneracies. For instance\, the Tricritical Ising model deformed by the subleading Z2 odd operator flows to a gapped phase with two degenerate vacua. This flow enjoys a Fibonacci fusion category symmetry which implies a threefold degeneracy of its particle states\, relating the mass of solitons interpolating between vacua and particles supported in a single vacuum.
URL:https://cmsa.fas.harvard.edu/event/gcs24_cordova/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Event,Symmetry Colloquia
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Pages-from-2403.08883_2.47.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240502T150000
DTEND;TZID=America/New_York:20240502T155000
DTSTAMP:20260503T092635
CREATED:20240415T163531Z
LAST-MODIFIED:20240417T181737Z
UID:10003357-1714662000-1714665000@cmsa.fas.harvard.edu
SUMMARY:Symmetry Colloquia  - Global Categorical Symmetries
DESCRIPTION:Symmetry Colloquia – Global Categorical Symmetries \nMay 2\, 2024 \nLocation: Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nSpeaker: Thomas Dumitrescu\, UCLA \nTitle: Symmetries\, Invertible Field Theories\, and Gauge Theory Phases \nAbstract: I will start with a brief overview of gauge theory phases in 3+1 dimensions through the lens of higher symmetries — in particular the realization of 1-form symmetries acting on loop order parameters. I will then review recent progress in refining this characterization using invertible field theories\, or equivalently symmetry protected topological phases (SPTs). This refinement leads to new results in gauge theories with fundamental matter\, such as quantum chromodynamics (QCD)\, which do not possess 1-form symmetries. I will explain why these theories must sometimes undergo a phase transition between their confining and Higgs regimes\, despite the fact that classic results and standard lore say they should be continuously connected.
URL:https://cmsa.fas.harvard.edu/event/gcs24_dumitrescu/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Event,Symmetry Colloquia
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Pages-from-2312.16898_phase-transition.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240502T163000
DTEND;TZID=America/New_York:20240502T172000
DTSTAMP:20260503T092635
CREATED:20240415T163546Z
LAST-MODIFIED:20240422T153733Z
UID:10003358-1714667400-1714670400@cmsa.fas.harvard.edu
SUMMARY:Symmetry Colloquia  - Global Categorical Symmetries
DESCRIPTION:Symmetry Colloquia – Global Categorical Symmetries \nMay 2\, 2024 \nLocation: Room G-10\, CMSA\, 20 Garden Street\, Cambridge MA 02138 \nSpeaker: Theo Johnson-Freyd\, Dalhousie University and Perimeter Institute \nTitle: The Universal Target Category \nAbstract: Hilbert’s Nullstellensatz says that the complex numbers C satisfy a universal property among all R-algebras: every not-too-large nonzero commutative R-algebra maps to C. Deligne proved a similar statement in categorical dimension 1: every not-too-large symmetric monoidal category over R maps to the category sVec of super vector spaces. In other words\, sVec (and not Vec!) is “algebraically closed”. These statements help explain why quantum field theory requires imaginary numbers and fermions. I will describe the universal symmetric monoidal higher category that extends the sequence C\, sVec\, …. This is joint work in progress with David Reutter\, and builds on closely-related work by GCS collaborators Freed\, Scheimbauer\, and Teleman and Schlank et al.
URL:https://cmsa.fas.harvard.edu/event/gcs24_johnson-freyd/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Event,Symmetry Colloquia
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Pages-from-2105.15167_Johnson-Freyd.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240503T110000
DTEND;TZID=America/New_York:20240503T120000
DTSTAMP:20260503T092635
CREATED:20240430T205406Z
LAST-MODIFIED:20240501T155445Z
UID:10003385-1714734000-1714737600@cmsa.fas.harvard.edu
SUMMARY:Mathematical Aspects of Scattering Amplitudes Lecture
DESCRIPTION:Mathematical Aspects of Scattering Amplitudes Lecture \nSpeaker: Andrew McLeod\, Edinburgh \nTitle: Genealogical Constraints on Feynman Integrals
URL:https://cmsa.fas.harvard.edu/event/scatteringamplitudes_5324/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Scattering Amplitudes Lectures
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240506T163000
DTEND;TZID=America/New_York:20240506T173000
DTSTAMP:20260503T092635
CREATED:20240319T201629Z
LAST-MODIFIED:20240507T201738Z
UID:10000819-1715013000-1715016600@cmsa.fas.harvard.edu
SUMMARY:Liouville Theory and Weil-Petersson Geometry
DESCRIPTION:Colloquium \nSpeaker: Sarah Harrison (Northeastern University) \nTitle: Liouville Theory and Weil-Petersson Geometry \nAbstract: Two-dimensional conformal field theory is a powerful tool to understand the geometry of surfaces. Liouville conformal field theory in the classical (large central charge) limit encodes the geometry of the moduli space of Riemann surfaces. I describe an efficient algorithm to compute the Weil–Petersson metric to arbitrary accuracy using Zamolodchikov’s recursion relation for conformal blocks\, focusing on examples of a sphere with four punctures and generalizations to other one-complex-dimensional moduli spaces. Comparison with analytic results for volumes and geodesic lengths finds excellent agreement. In the case of M_{0\,4}\, I discuss numerical results for eigenvalues of the Weil-Petersson Laplacian and connections with random matrix theory. \nBased on work with K. Coleville\, A. Maloney\, K. Namjou\, and T. Numasawa.
URL:https://cmsa.fas.harvard.edu/event/colloquium-5624/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-05.06.2024.docx-1.png
END:VEVENT
END:VCALENDAR