BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Uwe-Jens Wiese (University of Bern) DTSTART:20200528T133000Z DTEND:20200528T143000Z DTSTAMP:20260412T170731Z UID:tTmuQFTseminar/1 DESCRIPTION:Title: Asymptotically free quantum fields from dimensional reduction of di screte variables\nby Uwe-Jens Wiese (University of Bern) as part of t- \,T- & mu dependence in QFT\n\n\nAbstract\nQuantum Chromodynamics (QCD) is the (3+1)-d asymptotically free relativistic SU(3) gauge theory that is f ormulated in terms of fundamental quark and gluon fields. CP(N-1) models i n (1+1)-d have a global SU(N) symmetry and share many features with QCD. T hey are also asymptotically free\, have a non-perturbatively generated mas s gap\, and non-trivial theta vacuum states. CP(N-1) models can be regular ized unconventionally by using discrete SU(N) quantum spins forming a (2+1 )-d spin ladder that consists of n transversely coupled quantum spin chain s. The (1+1)-d asymptotically free CP(N-1) fields then emerge from dimensi onal reduction when n is increased. Even n leads to the vacuum angle theta =0\, while odd n leads to theta=pi. In a similar way\, gluon fields emerge naturally from the dimensional reduction of (4+1)-d quantum links\, which are discrete gauge variables that generalize quantum spins. In this formu lation\, quarks arise as domain wall fermions. In contrast to the usual qu antum fields\, quantum spins and quantum links realize asymptotically free field theories with finite-dimensional local Hilbert spaces. This is adva ntageous in the context of quantum simulation experiments. Both CP(N-1) mo dels and QCD can be quantum simulated with ultra-cold alkaline-earth atoms in optical super-lattices. When CP(N-1) models are studied at non-zero ch emical potential\, non-trivial condensed matter physics arises in these qu antum field theories. In particular\, there are Bose-Einstein condensates\ , with and without ferromagnetism.\n LOCATION:https://researchseminars.org/talk/tTmuQFTseminar/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Yi Yin (Quark Matter Research Center\, Institute of Modern Physics (Chinese Academy of Science)) DTSTART:20200611T133000Z DTEND:20200611T143000Z DTSTAMP:20260412T170731Z UID:tTmuQFTseminar/2 DESCRIPTION:Title: Quark-gluon plasma\, the QCD critical point and Hydro+\nby Yi Y in (Quark Matter Research Center\, Institute of Modern Physics (Chinese Ac ademy of Science)) as part of t-\,T- & mu dependence in QFT\n\n\nAbstract\ nHeavy-ion collisions at RHIC and LHC produce quark-gluon plasma (QGP) who se bulk evolution is well described by relativistic hydrodynamics. However \, to further explore the properties of QGP and the phase diagram of QCD\, one typically has to go beyond this hydrodynamic paradigm. In this talk\, I will present the development of a general dynamic framework which coupl es slow non-hydro. modes with hydro. modes\, namely Hydro+. I will demonst rate the application of Hydro+ to describe off-equilibrium dynamics near t he conjectured QCD critical point. If time permits\, I will briefly report my recent attempt to explore the dynamic properties of QGP in the non-hyd rodynamic yet non-perturbative regime.\n LOCATION:https://researchseminars.org/talk/tTmuQFTseminar/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Uwe-Jens Wiese (University of Bern) DTSTART:20200702T133000Z DTEND:20200702T143000Z DTSTAMP:20260412T170731Z UID:tTmuQFTseminar/3 DESCRIPTION:Title: Asymptotically free quantum fields from dimensional reduction of di screte variables (Part 2)\nby Uwe-Jens Wiese (University of Bern) as p art of t-\,T- & mu dependence in QFT\n\n\nAbstract\nQuantum Chromodynamics (QCD) is the (3+1)-d asymptotically free relativistic SU(3) gauge theory that is formulated in terms of fundamental quark and gluon fields. CP(N-1) models in (1+1)-d have a global SU(N) symmetry and share many features wi th QCD. They are also asymptotically free\, have a non-perturbatively gene rated mass gap\, and non-trivial theta vacuum states. CP(N-1) models can b e regularized unconventionally by using discrete SU(N) quantum spins formi ng a (2+1)-d spin ladder that consists of n transversely coupled quantum s pin chains. The (1+1)-d asymptotically free CP(N-1) fields then emerge fro m dimensional reduction when n is increased. Even n leads to the vacuum an gle theta=0\, while odd n leads to theta=pi. In a similar way\, gluon fiel ds emerge naturally from the dimensional reduction of (4+1)-d quantum link s\, which are discrete gauge variables that generalize quantum spins. In t his formulation\, quarks arise as domain wall fermions. In contrast to the usual quantum fields\, quantum spins and quantum links realize asymptotic ally free field theories with finite-dimensional local Hilbert spaces. Thi s is advantageous in the context of quantum simulation experiments. Both C P(N-1) models and QCD can be quantum simulated with ultra-cold alkaline-ea rth atoms in optical super-lattices. When CP(N-1) models are studied at no n-zero chemical potential\, non-trivial condensed matter physics arises in these quantum field theories. In particular\, there are Bose-Einstein con densates\, with and without ferromagnetism.\n LOCATION:https://researchseminars.org/talk/tTmuQFTseminar/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Markus Heyl (MPI Dresden) DTSTART:20200709T133000Z DTEND:20200709T143000Z DTSTAMP:20260412T170731Z UID:tTmuQFTseminar/4 DESCRIPTION:Title: Quantum many-body dynamics in two dimensions with artificial neural networks\nby Markus Heyl (MPI Dresden) as part of t-\,T- & mu depende nce in QFT\n\n\nAbstract\nThe efficient numerical simulation of nonequilib rium real-time evolution in isolated quantum matter constitutes a key chal lenge for current computational methods. This holds in particular in the r egime of two spatial dimensions\, whose experimental exploration is curren tly pursued with strong efforts in quantum simulators. In this work we pre sent a versatile and efficient machine learning inspired approach based on a recently introduced artificial neural network encoding of quantum many- body wave functions. We identify and resolve some key challenges for the s imulation of time evolution\, which previously imposed significant limitat ions on the accurate description of large systems and long-time dynamics. As a concrete example\, we study the dynamics of the paradigmatic two-dime nsional transverse field Ising model\, as recently also realized experimen tally in systems of Rydberg atoms. Calculating the nonequilibrium real-tim e evolution across a broad range of parameters\, we\, for instance\, obser ve collapse and revival oscillations of ferromagnetic order and demonstrat e that the reached time scales are comparable to or exceed the capabilitie s of state-of-the-art tensor network methods. [arXiv:1912.08828]\n LOCATION:https://researchseminars.org/talk/tTmuQFTseminar/4/ END:VEVENT END:VCALENDAR