This book is the second volume of the proceedings of the joint conference X. International Symposium "Quantum Theory and Symmetries" (QTS-X) and XII. International Workshop "Lie Theory and Its Applications in Physics" (LT-XII), 19-25 June 2017, Varna, Bulgaria. The QTS series started around the core concept that symmetries underlie all descriptions of quantum systems. It has since evolved into a symposium on the frontiers of theoretical and mathematical physics. The LT series covers the whole field of Lie Theory in its widest sense together with its applications in many facets of physics. As an interface between mathematics and physics the workshop serves as a meeting place for mathematicians and theoretical and mathematical physicists. In the division of the material between the two volumes, the Editor has tried to select for the first and second volumes papers that are more oriented toward mathematics and physics, respectively. However, this division is relative since many papers could have been placed in either volume. The topics covered in this volume represent the most modern trends in the fields of the joint conferences: symmetries in string theories, conformal field theory, holography, gravity theories and cosmology, gauge theories, foundations of quantum theory, nonrelativistic and classical theories.

Inhalt
Plenary Talks: Benjamin Basso, From Hexagons to Feynman Integrals.- Loriano Bonora, M. Cvitan, P. Dominis Prester, S. Giaccari, and T. Stemberga, Higher Spins from One-Loop Effective Actions.- Martin Cederwall, Algebraic Structures in Exceptional Geometry.- Sumit R. Das, Animik Ghosh, Antal Jevicki, Kenta Suzuki, Duality in the Sachdev-Ye-Kitaev Model.- Evgeny Ivanov, Implications of Hidden N = (0;1) Supersymmetry in 6D;N = (1;1) SYM Theory.- Ivan Kostov, Didina Serban, and Dinh-Long Vu, TBA and Tree Expansion.- Eduardo Guendelman, Emil Nissimov, and Svetlana Pacheva, Wheeler-DeWitt Quantization of Gravity Models of Unified Dark Energy and Dark Matter.- Dmitry Chicherin, Paul Heslop, Gregory P. Korchemsky, and Emery Sokatchev, Wilson Loop Form Factors: A New Duality.- Fumihiko Sugino and Pramod Padmanabhan, Many-Body Localization in Large-N Conformal Mechanics.- Generalized Bases with a Resolution of the Identity: A. Vourdas, A Cooperative Game Theory Approach.- Holography and String Theory, Lilia Anguelova, Peter Suranyi and L.C. Rohana Wijewardhana, On Non-slow Roll Inflationary Regimes.- Yuhma Asano, Veselin G. Filev, Samuel Kov´acik, Denjoe O'Connor, Precision Test of Holographic Flavourdynamics.- Alfredo Bonini, Davide Fioravanti, Simone Piscaglia, and Marco Rossi, N = 4 PolygonalWilson Loops: Fermions.- Yi Yang, Hidden Symmetry in String Theory.- H. Dimov, S. Mladenov, R. Rashkov, and T. Vetsov, Information Geometry of Strings on Plane Wave Background.- Gravity and Cosmology, C.I. Lazaroiu, C.S. Shahbazi, The Global Formulation of Generalized Einstein-Scalar-Maxwell Theories, Elena Mirela Babalic and Calin Iuliu Lazaroiu, Two-Field Cosmological Models and the Uniformization Theorem.- Dario Rosa, The Cohomological Structure of Generalized Killing Spinor Equations.- Denitsa Staicova and Michail Stoilov, Cosmological Solutions From Models with Unified Dark Energy and Dark Matter and with Inflaton Field.- Kalin Marinov and Plamen Fiziev, Relation between Dilatonic Pressure and Cosmological Pressure for Neutron Stars in Minimal Dilatonic Gravity.- Conformal and Gauge Theories, Satoshi Ohya, ConformalWard-Takahashi Identity at Finite Temperature, Marian Stanishkov, Renormalization in Some 2D b su(2) Coset Models.- Amalia Torre, Ambra Lattanzi and Decio Levi, Time-Dependent Free-Particle Salpeter Equation: Features of the Solutions.- Ovidiu Cristinel Stoica, Leptons, Quarks, and Gauge Symmetries, from a Clifford Algebra.- Foundations of Quantum Theory, Josef Janyska, Marco Modugno, Dirk Saller, Infinitesimal Symmetries in Covariant Quantum Mechanics.- Sara Botelho-Andrade, Peter G. Casazza, Desai Cheng, John Haas, and Tin T. Tran, The Quantum Detection Problem: A Survey.- Andr´as L´aszl´o, Possible Alternative Mechanism to Susy: Conservative Extensions of the Poincar´e Group.- Walter Smilga, Noether's Theorem and Its Complement in Multi-Particle Systems.- Enrico Celeghini, Manuel Gadella, and Mariano A. del Olmo, SU(2), Associated Laguerre Polynomials and Rigged Hilbert Spaces.- Nonrelativistic and Classical Theories, Asher Yahalom, Metage Symmetry Group of Non-Barotropic Magnetohydrodynamics and the Conservation of Cross Helicity.- Igor Salom and V. Dmitrasinovi´c, Three Quarks Confined by an Area-Dependent Potential in Two Dimensions.- Stam Nicolis, Pascal Thibaudeau, Thomas Nussle, A Group Action Principle for Nambu Dynamics of Spin Degrees of Freedom.- Roberto Auzzi, Newton-Cartan Trace Anomalies and Renormalization Group Flows.- E.I. Jafarov and S.M. Nagiyev, Evolution Operator Method and a Non-Relativistic Particle in the Time-Dependent Homogeneous Field.