String theory and related subjects Marios Petropoulos Centre de Physique Théorique, Ecole Polytechnique ICFP Theoretical Physics What is string theory? • Worldwide scientific activity • Branch of mathematical/theoretical physics • high-energy particle physics • gravity/cosmology • statistical mechanics/condensed matter • geormetry and more mathematical topics A few words on particle physics ... • Since 1931 (Berkeley) particles are produced in accelerators and colliders • at high energy: relativistic c • at microscopic scales: quantum ħ • Particles and interactions studied with relativistic quantum mechanics: Quantum Field Theory • Culminated in the 70’s with a gauge theory: the Standard Model Note: QFT is a tool used in statistical mechanics and condensed matter ... and gravity • Described since 1916 by a classical field theory named General Relativity • Verified with high precision in the solar system and beyond: mercury perihelion precession, Shapiro effect, pulsars, GPS • Successfully applied to cosmology: Big-Bang and further evolution • Hard to reconcile with ħ: non-renormalizable QFT String theory historically • Prehistory : dual models (1967-1974) • History : theory of gravity (1974-1984) • Modern ages : theory of everything (1984-2000) • Maturity : toolbox like and beyond QFT (2000-) String theory ideally • The point-like object is abandoned • The techniques include QFT • The output is the possibility for various particles and interactions to emerge ... • ... in particular gauge theories & quantum gravity defined in 10 space-time dimensions String theory practically • Quantum gravity • supergravity • various aspects of black holes such as black-hole thermodynamics ... • Grand-unified theory • analyse compactifications: geometry • comply with SM: phenomenology, supersymmetry String theory practically • Cosmology • initial singularity • cosmological evolution • More generally • develop techniques beyond QFT, dualities ... • understand (and prove?) holography: integrability • apply holographic correspondence to QCD, condensed-matter systems, superfluids ... String theory within ICFP • Introduction to String Theory in the second semester • Based on a good practice in Quantum Field Theory, Statistical Field Theory and General Relativity (first semester) • Naturally combined with Gauge Theory and Electroweak Interactions, Introduction to Quantum Chromodynamics and many others courses String theory in the area of Paris • Active groups in many laboratories • LPT - Ecole Normale Supérieure • LPTHE - Université de Paris 6 (Jussieu) • APC - Université de Paris 7 (Tolbiac) • IPhT - CEA Saclay • IHES - Bures-sur-Yvette • CPHT - Ecole Polytechnique • Hosting PhD students and postdoctoral fellows • Common activities (seminars, funding programmes).