BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Igor Klebanov (Princeton U.) DTSTART:20200831T180000Z DTEND:20200831T190000Z DTSTAMP:20260423T010458Z UID:UKYhepth/3 DESCRIPTION:Title: Breaking of Discrete and Continuous Symmetries in Coupled SYK or Tensor M odels\nby Igor Klebanov (Princeton U.) as part of Theoretical Physics Seminars (Kentucky)\n\n\nAbstract\nAbstract : \n\nA large number of Majora na fermions with interactions coupling four of them at a time can exhibit interesting quantum dynamics. Models of this kind include the Sachdev-Ye-K itaev (SYK) model\, where the coefficients of quartic interactions are ran domly distributed\, and the Tensor models\, where they respect continuous symmetries. These models exhibit approximate invariance under scaling of t he time and have power law fall-off of the correlation functions.\n\nIn th is talk we will discuss a pair of SYK or Tensor models coupled by the quar tic interactions\, and show that they produce a richer set of phenomena. T hese include a line of fixed points\, where critical exponents vary along the line and formally acquire imaginary parts outside it. For one sign of the coupling constant\, the approximate scale invariance continues to hold . For the other\, a gap opens in the energy spectrum\, resulting in expone ntial fall-off of correlation functions. This is indicative of breaking of a discrete symmetry. Thus\, our quantum mechanical model exhibits dynamic al phenomena characteristic of higher dimensional quantum field theories. Furthermore\, the gapped phase of our model may be dual to a certain trave rsable wormhole in two-dimensional space-time.\n\nThe talk will end with a similar discussion of a pair of complex SYK models coupled by a quartic i nteraction which preserves the U(1) x U(1) symmetry. For a range of parame ters\, this model gives rise to breaking of one of the U(1) symmetries. Th is is demonstrated via an analysis of the large N Dyson-Schwinger equation s\, as well as by Exact Diagonalizations of the finite N Hamiltonians.\n\n Zoom: https://uky.zoom.us/j/97553578130\n LOCATION:https://researchseminars.org/talk/UKYhepth/3/ END:VEVENT END:VCALENDAR