BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251109T032128EST-4898uz2uUv@132.216.98.100 DTSTAMP:20251109T082128Z DESCRIPTION:Title: The C^3 problem: error-correcting codes with a constant rate\, constant distance\, and constant locality.\n\n \n\nAbstract: An err or-correcting code is locally testable (LTC) if there is a random tester t hat reads only a constant number of bits of a given word and decides wheth er the word is in the code\, or at least close to it.\n\nA long-standing p roblem asks if there exists such a code that also satisfies the golden sta ndards of coding theory: constant rate and constant distance. Unlike the c lassical situation in coding theory\, random codes are not LTC\, so this p roblem is a challenge of a new kind.\n\nWe construct such codes based on w hat we call (Ramanujan) Left/Right Cayley square complexes. These\n\n2-dim ensional objects seem to be of independent interest.\n\nThe lecture will b e self-contained.\n\n\n  \n DTSTART:20211124T200000Z DTEND:20211124T210000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Alex Lubotzky (Hebrew Univ / Weizmann Institute / IAS) URL:/mathstat/channels/event/alex-lubotzky-hebrew-univ -weizmann-institute-ias-335056 END:VEVENT END:VCALENDAR