BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CMSA - ECPv6.17.1//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH 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:20200308T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20201101T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20210314T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20211107T060000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT DTSTART:20220313T070000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0400 TZOFFSETTO:-0500 TZNAME:EST DTSTART:20221106T060000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=America/New_York:20211104T184600 DTEND;TZID=America/New_York:20211104T204600 DTSTAMP:20240301T103919Z CREATED:20240214T080650Z LAST-MODIFIED:20240301T103919Z UID:10002580-1636051560-1636058760@cmsa.fas.harvard.edu SUMMARY:11/4/21 CMSA Interdisciplinary Science Seminar DESCRIPTION:Title: Exploring Invertibility in Image Processing and Restoration \nAbstract: Today’s smartphones have enabled numerous stunning visual effects from denoising to beautification\, and we can share high-quality JPEG images easily on the internet\, but it is still valuable for photographers and researchers to keep the original raw camera data for further post-processing (e.g.\, retouching) and analysis. However\, the huge size of raw data hinders its popularity in practice\, so can we almost perfectly restore the raw data from a compressed RGB image and thus avoid storing any raw data? This question leads us to design an invertible image signal processing pipeline. Then we further explore invertibility in other image processing and restoration tasks\, including image compression\, reversible image conversion (e.g.\, image-to-video conversion)\, and embedding novel views in a single JPEG image. We demonstrate that customized invertible neural networks are highly effective in these inherently non-invertible tasks. URL:https://cmsa.fas.harvard.edu/event/11-4-21-cmsa-interdisciplinary-science-seminar/ CATEGORIES:Interdisciplinary Science Seminar ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/CMSA-Interdisciplinary-Science-Seminar-11.04.21-1583x2048-1-1.jpg END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20211111T142200 DTEND;TZID=America/New_York:20211111T152200 DTSTAMP:20240301T103744Z CREATED:20240301T103744Z LAST-MODIFIED:20240301T103744Z UID:10002893-1636640520-1636644120@cmsa.fas.harvard.edu SUMMARY:11/11/21 Interdisciplinary Science Seminar DESCRIPTION:Title: The Kervaire conjecture and the minimal complexity of surfaces \nAbstract: We use topological methods to solve special cases of a fundamental problem in group theory\, the Kervaire conjecture.\nThe conjecture asserts that\, for any nontrivial group G and any element w in the free product G*Z\, the quotient (G*Z)/<> is still nontrivial. We interpret this as a problem of estimating the minimal complexity (in terms of Euler characteristic) of surfaces in HNN extensions. This gives a conceptually simple proof of Klyachko’s theorem that confirms the Kervaire conjecture for any G torsion-free. I will also explain new results obtained using this approach. URL:https://cmsa.fas.harvard.edu/event/11-11-21-interdisciplinary-science-seminar/ CATEGORIES:Interdisciplinary Science Seminar ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Interdisciplinary-Science-Seminar-11.11.21.png END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/New_York:20211118T142500 DTEND;TZID=America/New_York:20211118T152500 DTSTAMP:20240301T103505Z CREATED:20240214T075510Z LAST-MODIFIED:20240301T103505Z UID:10002572-1637245500-1637249100@cmsa.fas.harvard.edu SUMMARY:11/18/2021 Interdisciplinary Science Seminar DESCRIPTION:Title: Amplituhedra\, Scattering Amplitudes and Triangulations \nAbstract: In this talk I will discuss about Amplituhedra – generalizations of polytopes inside the Grassmannian – recently introduced by physicists as new geometric constructions encoding interactions of elementary particles in certain Quantum Field Theories. In particular\, I will explain how the problem of finding triangulations of Amplituhedra is connected to computing scattering amplitudes of N=4 super Yang-Mills theory. Triangulations of polygons are encoded in the associahedron studied by Stasheff in the sixties; in the case of polytopes\, triangulations are captured by secondary polytopes constructed by Gelfand et al. in the nineties. Whereas a “secondary” geometry describing triangulations of Amplituhedra is still not known\, and we pave the way for such studies. We will discuss how the combinatorics of triangulations interplays with T-duality from String Theory\, in connection with a dual object we define – the Momentum Amplituhedron. A generalization of T-duality led us to discover a striking duality between triangulations of Amplituhedra of “m=2” type and the ones of a seemingly unrelated object – the Hypersimplex. The latter is a polytope which has been central in many contexts\, such as matroid theory\, torus orbits in the Grassmannian\, and tropical geometry. Based on joint works with Lauren Williams\, Melissa Sherman-Bennett\, Tomasz Lukowski [arXiv:2104.08254\, arXiv:2002.06164]. URL:https://cmsa.fas.harvard.edu/event/11-18-2021-interdisciplinary-science-seminar/ CATEGORIES:Interdisciplinary Science Seminar END:VEVENT END:VCALENDAR