Open+problems

Below is given a collection of open problems and conceptual questions, that were collected from the participants of this program during the first discussion session (on Oct. 19th). Everybody is welcome to contribute to this list, such as to extend/correct/clarify it.

>> >> >> >> >>
 * **Fermions in 2D and 3D:**
 * Which methods do we have? Where do they work?
 * Can we understand the nodal structure?
 * **Frustrated magnets and exotic phases:**
 * How do we characterize critical spin liquids?
 * How do we characterize non-Fermi liquids of itinerant electrons?
 * Can we find a "reasonably looking" spin-1/2 model with (e.g.) SU(2) symmetry that has a spin liquid ground state?
 * Is a continuous transition from a metal to a Mott insulator possible?
 * How do we connect to experimental measurements?
 * **Non-equilibrium physics:**
 * How can we formulate concepts such as universality in non-equilibrium situations and for open systems?
 * How can we directly simulate in the stationary state?
 * Spin-transport: For which models can we calcuate the Drude weight?
 * **Quantum information and Wavefunctions:**
 * How useful are variational wavefunctions?
 * Do good compact and calculateable variational wavefunctions and density matrices exist?
 * What is the relationship between the ground state and effective field theories?
 * Is entanglement entropy good to detect phases?
 * Do localized correlations correspond to area laws?
 * How much can we learn from a ground state wavefunction (of a gapped system) e.g. concerning topological properties?
 * What are bounds on the entanglement entropy for local Hamiltonians?
 * **Methods:**
 * What is the prospect of sampling Feynman diagrams to high orders (diagrammatic MC)?
 * How should we simulate systems with many internal d.o.f. (cf. ultracold molelcules)?
 * How well does DMFT work? How can we benchmark it?
 * What is the potential of bosonic DMFT (real-time dynamics)?
 * How can we explore impurities to serve as indicators/probe for phases?
 * How to perform analytical continuations?
 * Is the real-time evolution of an open quantum system (in which Schroedinger cats die quickly) easier to simulate than for a closed system?
 * **Which models should we simulate (next)?**


 * Scene from the session:**


 * Final list of questions (at the first discussion session; no doubt that the list will grow during the program :-) )**