BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CMSA - ECPv6.15.18//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:CMSA X-ORIGINAL-URL:https://cmsa.fas.harvard.edu X-WR-CALDESC:Events for CMSA REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:America/New_York BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20220313T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20221106T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20230312T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20231105T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20240310T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20241103T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20250309T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20251102T060000 END:STANDARD END:VTIMEZONE BEGIN:VTIMEZONE TZID:America/New_York BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20220313T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20221106T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20230312T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20231105T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20240310T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20241103T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20250309T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20251102T060000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=America/New_York:20231120T090000 DTEND;TZID=America/New_York:20231120T103000 DTSTAMP:20260503T095056 CREATED:20240108T175825Z LAST-MODIFIED:20240222T055339Z UID:10001130-1700470800-1700476200@cmsa.fas.harvard.edu SUMMARY:CMSA/Tsinghua Math-Science Literature Lecture: Scott Kominers DESCRIPTION:CMSA/Tsinghua Math-Science Literature Lecture \n \nProf. Scott Kominers will present a lecture in the CMSA/Tsinghua Math-Science Literature Lecture Series. \nDate: Monday\, November 20\, 2023 \nTime: 9:00 – 10:30 am ET \nLocation: Via Zoom Webinar \nTitle: 60 Years of Matching: From Gale and Shapley to Trading Networks \nAbstract: Gale and Shapley’s 1962 American Mathematical Monthly paper\, “College Admissions and the Stability of Marriage\,” is by now one of the most cited articles in the journal’s history\, having served as the foundation for an entire branch of the field of market design. This success owes in large part to the beautiful\, applicable\, and surprisingly general theory of matching mechanisms uncovered in Gale and Shapley’s work. This talk traces the history and evolution of matching theory from that paper forward to the present day\, along the way touching on real-world applications to everything from medical residency matching to electricity markets. \nModerator: Sergiy Verstyuk \n\nBeginning in Spring 2020\, the CMSA began hosting a lecture series on literature in the mathematical sciences\, with a focus on significant developments in mathematics that have influenced the discipline\, and the lifetime accomplishments of significant scholars. \n  \nCMSA COVID-19 Policies URL:https://cmsa.fas.harvard.edu/event/mathscilit2023/ LOCATION:Virtual CATEGORIES:Event,Math Science Literature Lecture Series ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Mathlit_Kominers_8.5x11.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231120T140000 DTEND;TZID=America/New_York:20231120T150000 DTSTAMP:20260503T095056 CREATED:20240222T103744Z LAST-MODIFIED:20240222T105558Z UID:10002800-1700488800-1700492400@cmsa.fas.harvard.edu SUMMARY:Emergent composite-fermion Luttinger liquid at the half-filled Landau level DESCRIPTION:Topological Quantum Matter Seminar \nSpeaker: Prashant Kumar\, University of Chicago \nTitle: Emergent composite-fermion Luttinger liquid at the half-filled Landau level \nAbstract: The half-filled Landau level is a fascinating point in the phase diagram of quantum Hall effect that has been hypothesized to be a non-Fermi liquid where composite-fermions (CFs) emerge at low energies. In this talk\, I will present our numerical calculations of the excitation spectrum of this state on infinite cylinders. By comparing our results with a quasi-1D theory of CFs\, we show compelling quantitative evidence for the emergence of a Luttinger liquid of composite-fermions at low energies\, distinct from that of electrons. I will comment on some future directions. URL:https://cmsa.fas.harvard.edu/event/tqms_112023/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Topological Quantum Matter Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Topological-Seminar-11.20.23-1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231120T163000 DTEND;TZID=America/New_York:20231120T173000 DTSTAMP:20260503T095056 CREATED:20240223T080617Z LAST-MODIFIED:20240223T080617Z UID:10002833-1700497800-1700501400@cmsa.fas.harvard.edu SUMMARY:The analytical challenges of connectomics DESCRIPTION:Speaker: Jeff W. Lichtman (Harvard University) \nTitle: The analytical challenges of connectomics \nAbstract: Recent progress in generating synapse-level maps of brains\, a field known as connectomics\, brings both opportunities and challenges. The upside is that the biophysical instantiation of memories\, behaviors\, and knowledge will soon be before us. The downside is that no one knows exactly how to make sense of this data. I will show what connectomics data sets are and attempt to explain why it is so difficult to unravel their meaning. URL:https://cmsa.fas.harvard.edu/event/colloquium-112023/ 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-11.20.2023.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231122T160000 DTEND;TZID=America/New_York:20231122T173000 DTSTAMP:20260503T095056 CREATED:20240221T102006Z LAST-MODIFIED:20240221T102032Z UID:10002775-1700668800-1700674200@cmsa.fas.harvard.edu SUMMARY:Modulated Gauge Theories and Fracton Behavior in 2D DESCRIPTION:Quantum Matter Seminar \nSpeaker: Guilherme Delfino Silva (Boston University) \nTitle: Modulated Gauge Theories and Fracton Behavior in 2D \nAbstract: In this talk we investigate deconfined phases of two-dimensional ZN lattice gauge theories associated to spatially modulated symmetries. In order to study the low-energy physics of such modulated gauge theories we propose and explore exactly solvable gapped Hamiltonians\, which allow us to fully characterize their low-energy properties at zero temperature. We provide explicit examples and discuss how non-polynomial symmetries\, as exponential symmetries\, are powerful enough to fully constrain the mobility of isolated excitations. URL:https://cmsa.fas.harvard.edu/event/qm_112223/ 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-11.22.2023..png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231127T103000 DTEND;TZID=America/New_York:20231127T113000 DTSTAMP:20260503T095056 CREATED:20240221T113319Z LAST-MODIFIED:20240221T113411Z UID:10002783-1701081000-1701084600@cmsa.fas.harvard.edu SUMMARY:A p-adic Laplacian on the Tate curve DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: An Huang (Brandeis) \nPre-talk Speaker: TBA: 10:00-10:30 am \n\n\nTitle: A p-adic Laplacian on the Tate curve \nAbstract: We shall first explain the relation between a family of deformations of genus zero p-adic string worldsheet action and Tate’s thesis. We then propose a genus one p-adic string worldsheet action. The key is the definition of a p-adic Laplacian operator on the Tate curve. We show that the genus one p-adic Green’s function exists\, is unique under some obvious constraints\, is locally constant off diagonal\, and has a reflection symmetry. It can also be numerically computed exactly off the diagonal\, thanks to some simplifications due to the p-adic setup. Numerics suggest that at least in some special cases\, the asymptotic behavior of the Green’s function near the diagonal is a direct p-adic counterpart of the familiar Archimedean case\, although the p-adic Laplacian is not a local operator. Joint work in progress with Rebecca Rohrlich. URL:https://cmsa.fas.harvard.edu/event/agst-112723/ 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/CMSA-Algebraic-Geometry-in-String-Theory-11.27.2023.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231127T163000 DTEND;TZID=America/New_York:20231127T173000 DTSTAMP:20260503T095056 CREATED:20240223T080018Z LAST-MODIFIED:20240223T080018Z UID:10002831-1701102600-1701106200@cmsa.fas.harvard.edu SUMMARY:What do topological dynamics\, combinatorics\, and model theory have in common? DESCRIPTION:Speaker: Dana Bartosova (University of Florida) \nTitle: What do topological dynamics\, combinatorics\, and model theory have in common? \nAbstract: A striking correspondence between dynamics of automorphism groups of countable first order structures and Ramsey theory of finitary approximation of the structures was established in 2005 by Kechris\, Pestov\, and Todocevic. Since then\, their work has been generalized and applied in many directions. It also struck a fresh wave of interest in finite Ramsey theory.  Many classes of finite structures are shown to have the Ramsey property by encoding their problem in a known Ramsey class and translating a solution back. This is often a case-by-case approach and naturally there is a great need for abstracting the process. There has been much success on this front\, however\, none of the tools captures every situation. We will discuss one such encoding via a model-theoretic notion of semi-retraction introduced by Lynn Scow in 2012. In a joint work\, we showed that a semi-retraction transfers the Ramsey property from one class of structures to another under quite general conditions. We compare semi-retractions to a category-theoretical notion of pre-adjunction revived by Mašulović in 2016. If time permits\, I will mention a transfer theorem of the Ramsey property from a class of finite structures to their uncountable ultraproducts\, which is an AIMSQuaRE project with Džamonja\, Patel\, and Scow. URL:https://cmsa.fas.harvard.edu/event/colloquium-112723/ 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-11.27.2023_Page_1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231128T110000 DTEND;TZID=America/New_York:20231128T120000 DTSTAMP:20260503T095056 CREATED:20240223T051146Z LAST-MODIFIED:20240223T051146Z UID:10002813-1701169200-1701172800@cmsa.fas.harvard.edu SUMMARY:Remarkable symmetries of rotating black holes DESCRIPTION:General Relativity Seminar \nSpeaker: David Kubiznak (Charles University) \nTitle: Remarkable symmetries of rotating black holes \nAbstract: It is well known that the Kerr geometry admits a non-trivial Killing tensor and its ‘square root’ known as the Killing-Yano tensor. These two objects stand behind Carter’s constant of geodesic motion as well as allow for separability of test field equations in this background. The situation is even more remarkable in higher dimensions\, where a single object — the principal Killing-Yano tensor — generates a tower of explicit and hidden symmetries responsible for integrability of geodesics and separability of test fields around higher-dimensional rotating black holes. Interestingly\, similar yet different structure is already present for the slowly rotating black holes described by the `magic square’ version of the Lense-Thirring solution\, giving rise to a geometrically preferred spacetime that can be cast in the Painleve-Gullstrand form and admits a tower of exact rank-2 and higher rank Killing tensors whose number rapidly grows with the number of spacetime dimensions. URL:https://cmsa.fas.harvard.edu/event/gr_112823/ CATEGORIES:General Relativity Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-11.28.23_Page_1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231128T120000 DTEND;TZID=America/New_York:20231128T130000 DTSTAMP:20260503T095056 CREATED:20240222T113148Z LAST-MODIFIED:20240222T113148Z UID:10002809-1701172800-1701176400@cmsa.fas.harvard.edu SUMMARY:A random matrix model towards the quantum chaos transition conjecture DESCRIPTION:Probability Seminar \nSpeaker: Jun Yin (UCLA) \nTitle: A random matrix model towards the quantum chaos transition conjecture \nAbstract: The Quantum Chaos Conjecture has long fascinated researchers\, postulating a critical spectrum phase transition that separates integrable systems from chaotic systems in quantum mechanics. In the realm of integrable systems\, eigenvectors remain localized\, and local eigenvalue statistics follow the Poisson distribution. Conversely\, chaotic systems exhibit delocalized eigenvectors\, with local eigenvalue statistics mirroring the Sine kernel distribution\, akin to the standard random matrix ensembles GOE/GUE. \nThis talk delves into the heart of the Quantum Chaos Conjecture\, presenting a novel approach through the lens of random matrix models. By utilizing these models\, we aim to provide a clear and intuitive demonstration of the same phenomenon\, shedding light on the intricacies of this long-standing conjecture. URL:https://cmsa.fas.harvard.edu/event/probability-112823/ CATEGORIES:Probability Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Special-Seminar-11.28.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231129T170000 DTEND;TZID=America/New_York:20231129T180000 DTSTAMP:20260503T095056 CREATED:20240221T100735Z LAST-MODIFIED:20240221T100813Z UID:10002773-1701277200-1701280800@cmsa.fas.harvard.edu SUMMARY:Anomalous Landau level analog in solids: search and implications for 2d heterostructures DESCRIPTION:Topological Quantum Matter Seminar \nSpeaker: Valentin Crepel\, Flatiron Institute \nTitle: Anomalous Landau level analog in solids: search and implications for 2d heterostructures \nAbstract: The recent experimental observation of fractional Chen insulators — the analog of fractional quantum Hall states realized in absence of any applied magnetic field — calls for more detailed theoretical investigations of the special conditions allowing their emergence. To gain some insight on this problem\, we can rely on (i) our extensive knowledge of the physical properties of Landau levels\, and (ii) the identification of their exact solid state analogs. \nIn this talk\, (i-ii) will be discussed in the case of ”anomalous Landau levels”\, which are protected by an index theorem\, and whose most famous representative are the zero-th Landau levels of graphene. In particular\, I will derive the generic form of Bloch wave functions realizing the analog of such anomalous Landau levels\, and argue that twisted transition metal dichalcogenides homobilayers (in which fractional Chern insulators were first discovered) almost realize such anomalous bands. URL:https://cmsa.fas.harvard.edu/event/tqms_112923/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Topological Quantum Matter Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Topological-Seminar-11.29.23.docx-1_Page_1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231130T160000 DTEND;TZID=America/New_York:20231130T170000 DTSTAMP:20260503T095056 CREATED:20240223T052452Z LAST-MODIFIED:20240223T052528Z UID:10002815-1701360000-1701363600@cmsa.fas.harvard.edu SUMMARY:A Gaussian convexity for logarithmic moment generating function DESCRIPTION:Probability Seminar \nSpeaker: Wei-Kuo Chen (University of Minnesota) \nTitle: A Gaussian convexity for logarithmic moment generating function \nAbstract: Convex functions of Gaussian vectors are prominent objectives in many fields of mathematical studies. In this talk\, I will establish a new convexity for the logarithmic moment generating function for this object and draw two consequences. The first leads to the Paouris-Valettas small deviation inequality that arises from the study of convex geometry. The second provides a quantitative bound for the Dotsenko-Franz-Mezard conjecture in the Sherrington-Kirkpatrick mean-field spin glass model\, which states that the logarithmic anneal partition function of negative replica is asymptotically equal to the free energy. \n  URL:https://cmsa.fas.harvard.edu/event/probability-113023/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Probability Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-11.30.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231201T120000 DTEND;TZID=America/New_York:20231201T130000 DTSTAMP:20260503T095056 CREATED:20240227T112716Z LAST-MODIFIED:20240227T112731Z UID:10002878-1701432000-1701435600@cmsa.fas.harvard.edu SUMMARY:An introduction to mixture of experts in deep learning DESCRIPTION:Member Seminar \nSpeaker: Samy Jelassi \nTitle: An introduction to mixture of experts in deep learning \nAbstract: Scale has opened new frontiers in natural language processing – but at a high cost. Mixture-of-Experts (MoE) have been proposed as a path to even larger and more capable language models. They select different parameters for each incoming example. By doing so\, the parameter count is decoupled from the compute per example leading to very large\, but efficient models. In this talk\, I will review the concept of mixture of experts\, provide a basic description of the Switch Transformers model\, characterize some of their behaviors and conclude by highlighting some open problems in the field. This talk is mainly based on the following papers: https://arxiv.org/pdf/2101.03961.pdf\, https://arxiv.org/pdf/2209.01667.pdf . URL:https://cmsa.fas.harvard.edu/event/member-seminar-12123/ 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:20231201T163000 DTEND;TZID=America/New_York:20231201T173000 DTSTAMP:20260503T095056 CREATED:20230802T170029Z LAST-MODIFIED:20240813T162053Z UID:10001173-1701448200-1701451800@cmsa.fas.harvard.edu SUMMARY:A Plane Defect in the 3d O(N) Model DESCRIPTION:Quantum Matter Seminar \nSpeaker: Abijith Krishnan (MIT) \nTitle: A Plane Defect in the 3d O(N) Model \nAbstract: It was recently found that the classical 3d O(N) model in the semi-infinite geometry can exhibit an “extraordinary-log” boundary universality class\, where the spin-spin correlation function on the boundary falls off as (log x)^(-q). This universality class exists for a range 2≤N3. In this talk\, I’ll extend this result to the 3d O(N) model in an infinite geometry with a plane defect. I’ll explain using the renormalization group (RG) that the extraordinary-log universality class is present for any finite N≥2\, and that a line of defect fixed points is present at N=∞. This line of defect fixed points is lifted to the ordinary\, special (no defect) and extraordinary-log universality classes by 1/N corrections. I’ll show that the line of defect fixed points and the 1/N corrections agree with an a-theorem by Jensen and O’Bannon for 3d CFTs with a boundary. Finally\, I’ll conclude by noting some physical systems where the extraordinary-log universality class can be observed. \n  URL:https://cmsa.fas.harvard.edu/event/qm_33123/ LOCATION:Hybrid CATEGORIES:Quantum Matter ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Topological-Seminar-12.01.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231201T163000 DTEND;TZID=America/New_York:20231201T173000 DTSTAMP:20260503T095056 CREATED:20240222T101228Z LAST-MODIFIED:20240222T103010Z UID:10002799-1701448200-1701451800@cmsa.fas.harvard.edu SUMMARY:Quantum information: the interplay of mathematics and physics DESCRIPTION:Topological Quantum Matter Seminar \nSpeaker: Kaifeng Bu (Harvard University) \nTitle: Quantum information: the interplay of mathematics and physics \nAbstract: I will provide an introduction to quantum information\, which points to a new connection with experiment on the one hand\, and a potential new area of mathematical analysis on the other. I will introduce two recent results about the application of this new area in quantum information: (1) a novel Quantum Central Limit Theorem (QCLT)\, and (2) a physically realizable protocol for testing and measuring quantum advantage. This talk is based on a collaboration with Arthur Jaffe\, and Weichen Gu (PNAS120(25)2023\, arXiv: 2302.08423\, arXiv:2306.09292). \n  URL:https://cmsa.fas.harvard.edu/event/tqms_12123/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Topological Quantum Matter Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Topological-Seminar-12.01.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231204T103000 DTEND;TZID=America/New_York:20231204T113000 DTSTAMP:20260503T095056 CREATED:20240222T065433Z LAST-MODIFIED:20240222T152910Z UID:10002786-1701685800-1701689400@cmsa.fas.harvard.edu SUMMARY:CM-minimizers and standard models of Fano fibrations over curves DESCRIPTION:Algebraic Geometry in String Theory Seminar \n\nSpeaker: Maksym Fedorchuk (Boston College) \nTitle: CM-minimizers and standard models of Fano fibrations over curves \nAbstract: A recent achievement in K-stability of Fano varieties is an algebro-geometric construction of a projective moduli space of K-polystable Fanos. The ample line bundle on this moduli space is the CM line bundle of Tian. One of the consequences of the general theory is that given a family of K-stable Fanos over a punctured curve\, the polystable filling is the one that minimizes the degree of the CM line bundle after every finite base change. A natural question is to ask what are the CM-minimizers without base change. In answering this question\, we arrive at a theory of Koll\’ar stability for fibrations over one-dimensional bases\, and standard models of Fano fibrations. I will explain the joint work with Hamid Abban and Igor Krylov in which we show that the CM-minimizers for del Pezzo fibrations are Corti’s standard models and related work in progress on quartic threefold hypersurfaces. \n\n  URL:https://cmsa.fas.harvard.edu/event/agst-12423/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Algebraic Geometry in String Theory Seminar ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/CMSA-AGIST-12.04.23-scaled.jpg END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231204T140000 DTEND;TZID=America/New_York:20231204T150000 DTSTAMP:20260503T095056 CREATED:20240226T112024Z LAST-MODIFIED:20240226T112046Z UID:10002869-1701698400-1701702000@cmsa.fas.harvard.edu SUMMARY:The Fractional Quantum Hall Effect at ν=5/2: Past\, Recent\, and Future DESCRIPTION:Topological Quantum Matter Seminar \nSpeaker:  Ken K. W. Ma (Northeastern University) \nTitle: The Fractional Quantum Hall Effect at ν=5/2: Past\, Recent\, and Future \nAbstract: The discovery of fractional quantum Hall (FQH) states started a new chapter in modern physics. Nowadays\, more than 70 FQH states at different filling factors have been observed. Among them\, the FQH state at the filling factor ν=5/2 in GaAs (or the 5/2 state) remains one of the most special and attractive states. Since its discovery in 1987\, different possible topological orders have been proposed to describe the 5/2 state. Some of them can host an exotic type of particles\, known as non-Abelian anyons. Recent experiments have provided more insights into the understanding of the 5/2 state\, but its underlying nature is still under debate. \nIn this talk\, I will review the basics of the 5/2 state [1] and a more unified theoretical description of different possible topological orders of the 5/2 state that we have recently proposed [2]. I will also review the groundbreaking thermal Hall conductance experiment [3] and the follow-up quantum Hall interface experiments by the Weizmann Institute group [4\, 5]\, and discuss what possible lessons that we can learn from the experimental results. Lastly\, I will talk about some possible directions and related topics for future investigations. \nReferences: \n[1] K. K. W. Ma\, M. R. Peterson\, V. W. Scarola\, and K. Yang\, “Fractional quantum Hall effect at the filling factor ν = 5/2” in Encyclopedia of Condensed Matter Physics (Second Edition)\, edited by T. Chakraborty\, Academic Press (2024).\n[2] K. K. W. Ma and D. E. Feldman\, “The sixteenfold way and the quantum Hall effect at half-integer filling factors”\, Phys. Rev. B 100\, 035302 (2019).\n[3] M. Banerjee\, M. Heiblum\, V. Umansky\, D. E. Feldman\, Y. Oreg\, and A. Stern\, “Observation of half-integer thermal Hall conductance”\, Nature (London) 559\, 205 (2018).\n[4] B. Dutta\, W. Yang\, R. Melcer\, H. K. Kundu\, M. Heiblum\, V. Umansky\, Y. Oreg\, A. Stern\, D. Mross\, “Distinguishing between non-Abelian topological orders in a quantum Hall system”\, Science 375\, 193 (2021).\n[5] B. Dutta\, V. Umansky\, M. Banerjee\, and M. Heiblum\, “Isolated ballistic non-Abelian interface channel”\, Science 377\, 1198 (2022). \n  URL:https://cmsa.fas.harvard.edu/event/tqms_12423/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Topological Quantum Matter Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Topological-Seminar-12.04.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231204T163000 DTEND;TZID=America/New_York:20231204T173000 DTSTAMP:20260503T095056 CREATED:20240223T075301Z LAST-MODIFIED:20240223T075301Z UID:10002830-1701707400-1701711000@cmsa.fas.harvard.edu SUMMARY:Analysis of ALH* gravitational instantons DESCRIPTION:Speaker: Xuwen Zhu (Northeastern) \nTitle: Analysis of ALH* gravitational instantons \nAbstract: Gravitational instantons are non-compact Calabi-Yau metrics with L^2 bounded curvature and are categorized into six types. We will discuss one such type called ALH* metrics which has a non-compact end modelled by the Calabi ansatz with inhomogeneous collapsing near infinity. Such metrics appeared recently in the works on SYZ conjecture\, as well as the scaling bubble limits for codimension-3 collapsing of K3 surfaces\, where the study of its Laplacian played a central role. In this talk I will talk about the Fredholm mapping property and L^2 cohomology of such metrics. This is ongoing work joint with Rafe Mazzeo. URL:https://cmsa.fas.harvard.edu/event/colloquium-12423/ 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-12.04.2023.docx-1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231205T110000 DTEND;TZID=America/New_York:20231205T120000 DTSTAMP:20260503T095056 CREATED:20240226T112803Z LAST-MODIFIED:20240813T160712Z UID:10002870-1701774000-1701777600@cmsa.fas.harvard.edu SUMMARY:The Feynman propagator and self-adjointness DESCRIPTION:General Relativity Seminar \nSpeaker: Andras Vasy (Stanford) \nTitle: The Feynman propagator and self-adjointness \nAbstract: In this talk I will discuss the Feynman and anti-Feynman inverses for wave operators on certain Lorentzian manifolds; these are two inverses which from a microlocal analysis perspective are more natural than the standard causal (advanced/retarded) ones. For instance\, for the spectral family of the wave operator\, these are the natural inverses when the spectral parameter is non-real. Indeed\, I will explain that these connect to the self-adjointness of the wave operator\, and the positivity properties that follow. \n  URL:https://cmsa.fas.harvard.edu/event/gr_12523/ LOCATION:Virtual CATEGORIES:General Relativity Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-12.05.2023.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231205T123000 DTEND;TZID=America/New_York:20231205T133000 DTSTAMP:20260503T095056 CREATED:20240223T084615Z LAST-MODIFIED:20240223T084615Z UID:10002841-1701779400-1701783000@cmsa.fas.harvard.edu SUMMARY:CMSA Q and A Seminar 12/5/2023 DESCRIPTION:CMSA Q and A Seminar \nSpeakers: Mike Douglas (Harvard CMSA) and Anurag Anshu (Harvard Computer Science) \nTopics: \nMike Douglas: What are scaling laws in deep learning? \nAnurag Anshu: What’s the difference between classical information theory and quantum information theory (or classical computation vs quantum computation)? \n  URL:https://cmsa.fas.harvard.edu/event/cmsaqa_12523/ 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:20231207T130000 DTEND;TZID=America/New_York:20231207T140000 DTSTAMP:20260503T095056 CREATED:20240223T055715Z LAST-MODIFIED:20240223T055715Z UID:10002823-1701954000-1701957600@cmsa.fas.harvard.edu SUMMARY:Active structures and flows in living cells DESCRIPTION:Active Matter Seminar\n\n\nSpeaker: Michael Shelley (Flatiron) \nTitle: Active structures and flows in living cells \nAbstract: Flows in the fluidic interior of living cells can serve biological function or act as signatures of how intracellular forces are exerted. I’ll discuss examples of each. One is understanding the emergence of cell-spanning vortical flows in large developing egg cells\, while the other arises in studying the nature of force transduction in single cell embryos moving towards their first cell division. Both involve the cytoskeleton\, that set of polymers\, cross-linkers\, and molecular motors that underlie much of the active mechanics within cells\, and has led to the development of new coarse-grained active matter models and novel instabilities. URL:https://cmsa.fas.harvard.edu/event/am-12723/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Active Matter Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Active-Matter-Seminar-12.07.23.docx-1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231208T120000 DTEND;TZID=America/New_York:20231208T130000 DTSTAMP:20260503T095056 CREATED:20240227T112413Z LAST-MODIFIED:20240227T112426Z UID:10002877-1702036800-1702040400@cmsa.fas.harvard.edu SUMMARY:Open Problems in Physics and Novel Solutions from Math DESCRIPTION:Member Seminar \nSpeaker: Juven Wang \nTitle: Open Problems in Physics and Novel Solutions from Math \n  \nAbstract: (1) How do neutrinos obtain tiny mass and oscillate between e\, \mu\, \tau three flavors? What consists of Dark Matter? What causes leptogenesis and baryogenesis? \n(2) Why the Parity Symmetry is violated in the weak interaction? How do we quantum mechanically regularize and numerically simulate the Standard Model (chiral fermion/gauge theory) on the lattice in 3+1 spacetime dimensions? \n(3) Strong CP problem: Why is the neutron electric dipole moment nearly zero and QCD respects the CP = T symmetry? \n(4) Family/Generation problem: Why are there three families/generations of quarks and leptons? \nIn my talk\, I will sketch and propose novel solutions to these challenging open problems in physics based on my own work (available on arXiv\, some jointly with my collaborators). \nI will show that the eclectic cross-disciplinary fertilization of ideas between the Math-Physics geometry and topology\, Quantum Condensed Matter\, and High-Energy Physics (theory\, pheno\, lattice) can help solving these big problems. \nThe (1) answer relates to Ultra Unification: a Z_{16} class Atiyah-Patodi-Singer eta invariant (Baryon – Lepton)-protected topological superconductor and a symmetry-extended anomalous topological quantum field theory. \nThe (2) and (3) answers relate to a trivial cobordism class and Symmetric Mass Generation\, and disordering and removing the Pecci-Quinn axions. \nThe (4) answer has to do with the Hirzebruch signature and Atiyah-Singer index theorem\, gravitational Chern-Simons theory\, and 3 E8 quantum Hall states. \n  URL:https://cmsa.fas.harvard.edu/event/member-seminar-12823/ 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:20231208T143000 DTEND;TZID=America/New_York:20231208T160000 DTSTAMP:20260503T095056 CREATED:20240221T100009Z LAST-MODIFIED:20240221T100109Z UID:10002772-1702045800-1702051200@cmsa.fas.harvard.edu SUMMARY:Fermi surface symmetric mass generation and its application in nickelate superconductor DESCRIPTION:Joint Quantum Matter in Mathematics and Physics & Topological Quantum Matter Seminar \nSpeaker: Da-Chuan Lu (UCSD) \nTitle: Fermi surface symmetric mass generation and its application in nickelate superconductor \nAbstract: Symmetric mass generation (SMG) is a novel interaction-driven mechanism that generates fermion mass without breaking symmetry\, unlike the standard Anderson-Higgs mechanism. SMG can occur in the fermion system without quantum anomalies. In this talk\, I will focus on the SMG for the systems with finite fermion density\, i.e.\, the Fermi surface. I will discuss the Fermi surface anomaly and Fermi surface SMG. Lastly\, I will talk about its application in the newly found nickelate superconductors\, where the superconductivity emerges without a nearby spontaneous symmetry-breaking phase. URL:https://cmsa.fas.harvard.edu/event/qm_12823/ 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-Quantum-Matter_String-Seminar-12.08.2023.docx-2.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231211T103000 DTEND;TZID=America/New_York:20231211T113000 DTSTAMP:20260503T095056 CREATED:20240221T112820Z LAST-MODIFIED:20240221T112900Z UID:10002782-1702290600-1702294200@cmsa.fas.harvard.edu SUMMARY:M-theory on nodal Calabi-Yau 3-folds and torsion refined GV-invariants DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Thorsten Schimannek (Utrecht University) \n\nTitle: M-theory on nodal Calabi-Yau 3-folds and torsion refined GV-invariants \nAbstract: The physics of M-theory and Type IIA strings on a projective nodal CY 3-folds is determined by the geometry of a small resolution\, even if the latter is not Kähler. We will demonstrate this explicitly in the context of a family of Calabi-Yau double covers of P^3. Using conifold transitions\, we prove that the exceptional curves in any small resolution are torsion while M-theory develops a discrete gauge symmetry.This leads to a torsion refinement of the ordinary Gopakumar-Vafa invariants\, that is associated to the singular Calabi-Yau and captures the enumerative geometry of the non-Kähler resolutions. We further argue that twisted circle compactifications of the 5d theory are dual to IIA compactifications on the nodal CY 3-fold with a flat but topologically non-trivial B-field. As a result\, the torsion refined invariants are encoded in the topological string partition functions with different choices for the global topology of a flat B-field. \nThe talk is based on 2108.09311\, 2212.08655 (with S. Katz\, A. Klemm\, and E. Sharpe) and 2307.00047 (with S. Katz). URL:https://cmsa.fas.harvard.edu/event/agst-121123/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Algebraic Geometry in String Theory Seminar ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-12.11.2023-scaled.jpg END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231211T163000 DTEND;TZID=America/New_York:20231211T173000 DTSTAMP:20260503T095056 CREATED:20240223T074431Z LAST-MODIFIED:20240223T074431Z UID:10002828-1702312200-1702315800@cmsa.fas.harvard.edu SUMMARY:Homology\, higher derived limits\, and set theory DESCRIPTION:Colloquium \nSpeaker: Justin Moore (Cornell University) \nTitle: Homology\, higher derived limits\, and set theory \nAbstract: Singular homology has a number of well-known defects when used to study spaces such as the Hawaiian earring and solenoids. It may not reflect the “shape” of the space and can give counterintuitive information about its dimension. One remedy of this is to develop a homology theory based on approximating spaces by polyhedra\, computing their homologies\, and then taking a limit. This is the approach taken by Steenrod-Sitnikov homology and Lisica and Mardesic’s strong homology. Even within the class of locally compact second countable spaces though\, the properties of these homology theories — and the higher derived limits which underly them — are dependent on axioms of set theory beyond ZFC. Recently it was shown that it is consistent with (and therefore independent of) ZFC that strong homology and Steenrod Sitnikov homology coincide in the class of locally compact second countable spaces — and therefore each of these homology theories enjoys the desirable properties of the other. These results also point to how we might develop variants of these homology theories which enjoy their desirable properties\, but which are less sensitive to set theory. This is joint work with Nathaniel Bannister\, Jeff Bergfalk\, and Stevo Todorcevic. URL:https://cmsa.fas.harvard.edu/event/colloquium-121123/ 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-12.11.2023.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231214T143000 DTEND;TZID=America/New_York:20231214T160000 DTSTAMP:20260503T095056 CREATED:20240109T001602Z LAST-MODIFIED:20240109T001934Z UID:10001133-1702564200-1702569600@cmsa.fas.harvard.edu SUMMARY:When does a three-dimensions Chern-Simons theory have a time reversal symmetry? DESCRIPTION:Speaker: Roman Geiko (UCLA) \nTitle: When does a three-dimensions Chern-Simons theory have a time reversal symmetry? \nIn this talk\, I will discuss the time reversal invariance of (spin-) Chern-Simons theory in 3 dimensions at both classical and quantum levels. I will show how to obtain a complete classification of Abelian anyons with the time reversal symmetry expressed in terms of the higher Gauss sums. Then\, I will comment on the time reversal symmetry of Chern-Simons in the non-Abelian case. URL:https://cmsa.fas.harvard.edu/event/qm_121423/ LOCATION:Virtual CATEGORIES:Quantum Matter ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QMMP-12.14.2023.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231215T100000 DTEND;TZID=America/New_York:20231215T113000 DTSTAMP:20260503T095056 CREATED:20240222T093357Z LAST-MODIFIED:20240222T093357Z UID:10002796-1702634400-1702639800@cmsa.fas.harvard.edu SUMMARY:Exact lattice chiral symmetry in 2d gauge theory DESCRIPTION:Quantum Matter Seminar \nSpeaker: Aleksey Cherman (UMN) \nTitle: Exact lattice chiral symmetry in 2d gauge theory \nAbstract: Preserving the symmetries of massless fermions is a well-known challenge in lattice field theory.  I’ll discuss symmetry-preserving lattice regularizations of 2d QED with one and two flavors of Dirac fermions\, as well as the `3450′ chiral gauge theory. The construction leverages bosonization and recently-proposed modifications of Villain-type lattice actions. The internal global symmetries act just as locally on the lattice as they do in the continuum\, the anomalies are reproduced at finite lattice spacing\, and in each case we’ve found a sign-problem-free dual formulation. URL:https://cmsa.fas.harvard.edu/event/qm_121523/ LOCATION:Virtual CATEGORIES:Quantum Matter ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QMMP-12.15.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20231215T120000 DTEND;TZID=America/New_York:20231215T130000 DTSTAMP:20260503T095056 CREATED:20240227T111152Z LAST-MODIFIED:20240227T111152Z UID:10002876-1702641600-1702645200@cmsa.fas.harvard.edu SUMMARY:On compactness phenomena DESCRIPTION:Member Seminar \nSpeaker: Alejandro Poveda \nTitle: On compactness phenomena \nAbstract: In this presentation I shall be preoccupied with compactness phenomena in set theory. Compactness is the phenomenon by which the local properties of a mathematical structure determine its global behavior. This phenomenon is intrinsic to the very architecture of the mathematical universe and manifests to us in a cornucopia of forms. Over the past fifty years\, the study of compactness phenomena has been a cornerstone of research in set theory. This talk will present recent discoveries regarding compactness principles\, spanning classical themes like the tree property and stationary reflection\, while also forging novel connections with other topics\, such as Woodin’s HOD Conjecture. URL:https://cmsa.fas.harvard.edu/event/member-seminar-121523/ 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:20240124T140000 DTEND;TZID=America/New_York:20240124T150000 DTSTAMP:20260503T095056 CREATED:20240102T163450Z LAST-MODIFIED:20240125T165049Z UID:10000148-1706104800-1706108400@cmsa.fas.harvard.edu SUMMARY:Approaches to the formalization of differential geometry DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Heather Macbeth\, Fordham University \nTitle: Approaches to the formalization of differential geometry \nAbstract: In the last five years\, there has been early work on the computer formalization of differential geometry. I will survey the projects I am aware of. I will also describe two projects of my own\, as case studies for typical challenges. The first (joint with Floris van Doorn) is an exercise in developing suitable abstractions\, the second (joint with Mario Carneiro) is an exercise in developing suitable automation. URL:https://cmsa.fas.harvard.edu/event/nt-12424/ LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:New Technologies in Mathematics Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-01.24.2024.docx-1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20240126T093000 DTEND;TZID=America/New_York:20240126T110000 DTSTAMP:20260503T095056 CREATED:20240118T143433Z LAST-MODIFIED:20240118T192034Z UID:10000860-1706261400-1706266800@cmsa.fas.harvard.edu SUMMARY:Gauging spacetime inversions DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Daniel Harlow (MIT) \nTitle: Gauging spacetime inversions \nAbstract: Spacetime inversion symmetries such as parity and time reversal play a central role in physics\, but they are usually treated as global symmetries. In quantum gravity there are no global symmetries\, so any spacetime inversion symmetries must be gauge symmetries. In particular this includes CRT symmetry (in even dimensions usually combined with a rotation to become CPT)\, which in quantum field theory is always a symmetry and seems likely to be a symmetry of quantum gravity as well. I’ll discuss what it means to gauge a spacetime inversion symmetry\, and explain some of the more unusual consequences of doing this. In particular I’ll argue that the gauging of CRT is automatically implemented by the sum over topologies in the Euclidean gravity path integral\, that in a closed universe the Hilbert space of quantum gravity must be a real vector space\, and that in Lorentzian signature manifolds which are not time-orientable must be included as valid configurations of the theory. URL:https://cmsa.fas.harvard.edu/event/qm-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-01.26.23.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20240126T120000 DTEND;TZID=America/New_York:20240126T130000 DTSTAMP:20260503T095056 CREATED:20240102T203315Z LAST-MODIFIED:20240125T174129Z UID:10000803-1706270400-1706274000@cmsa.fas.harvard.edu SUMMARY:Anti-Iitaka conjecture in positive characteristic DESCRIPTION:CMSA Member Seminar \nSpeaker: Iacopo Brivio (Harvard) \nTitle: Anti-Iitaka conjecture in positive characteristic \nAbstract: Given a smooth projective variety\, its Kodaira dimension kappa(K_X) is an important invariant that measures the rate of growth of m-pluricanonical forms as a function of m. It serves as an higher-dimensional generalization of the genus of a Riemann surface. If f : X –> Y is a fibration with general fiber F\, a famous conjecture of Iitaka predicts the inequality kappa(K_X) \geq kappa(K_Y) + kappa(K_F). More recently it was shown by Chang that\, if the stable base locus of -K_X is vertical\, then the inequality kappa(-K_X) \leq kappa(-K_Y) + kappa(-K_F) holds. Both Iitaka’s conjecture and Chang’s theorem are known to fail in positive characteristic. In this talk I will explain how one can recover Chang’s theorem for a class of “tame” fibrations in characteristic p > 0. This is based on joint work with M. Benozzo and C.-K. Chang. URL:https://cmsa.fas.harvard.edu/event/member-seminar-12624/ 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-01.26.24.docx-1.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20240126T160000 DTEND;TZID=America/New_York:20240126T180000 DTSTAMP:20260503T095056 CREATED:20240103T210013Z LAST-MODIFIED:20240222T054337Z UID:10001109-1706284800-1706292000@cmsa.fas.harvard.edu SUMMARY:CMSA/MATH Bi-Annual Gathering DESCRIPTION:On Friday\, Jan. 26\, 2024 the CMSA will host the CMSA/MATH Bi-Annual Gathering for Harvard CMSA and Math affiliates in the CMSA Common Room at 20 Garden Street\, Cambridge MA 02138. URL:https://cmsa.fas.harvard.edu/event/cmsa-math_2924/ LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States CATEGORIES:Event END:VEVENT END:VCALENDAR