Theoretical Particle Physics Group (TPP) Banfi Calmet Hindmarsh Huber Jaeger Litim Sanz

Theoretical Particle Physics Common tool: Quantum Field Theory unravel the physics at the TeV energy scale by exploiting the LHC and other experiments understand the evolution of the universe in terms of the fundamental laws of physics explore the quantum nature of gravity and its implications for particle physics and cosmology

Particle Physics, Gravity and Cosmology What is quantum gravity? Effective theory approach to quantum gravity using QFT techniques Quantum gravity and particle physics: grand unification physics Probing quantum gravity in the very early universe Extreme cosmology (very early universe) Inflation models and links to particle physics (Higgs, Starobinsky inflation etc) Time variation of fundamental couplings and vacuum evolution What is dark matter? Can it be explained by a modification of GR? Is it a new form of matter (particle)? Gravitational waves and black holes as laboratories to test fundamental physics and strong field gravity Tests of GR, maybe even quantum gravity Tests of black hole physics, horizon Information theory and black holes Xavier Calmet

Particle Physics and Cosmology Mark Hindmarsh Production of Gravitational Waves in the Early Universe (MHI2) Violent processes in the early universe - such as phase transitions - would have generated gravitational waves. This project examines possible sources from new physics at very high energy, calculate the amplitude and frequency spectrum of the resulting gravitational waves, and assess the possibilities for detection by a future space-based gravitational wave observatory. Some prior experience of the numerical solution of differential equations (with e.g. Python or Matlab) is needed. Recommended modules: General Relativity, Quantum Field Theory, Early Universe.  Numerical simulations of phase transitions in the early Universe (MH11) Modern particle physics predicts that the very early Universe went through a series of phase transitions, which may have produced extended objects called topological defects.  This project studies phase transitions using numerical simulations: specific problems include the propagation and collision of phase boundaries, the formation and evolution of domain walls or cosmic strings. Basic knowledge of C is essential, and some familiarity with Unix would be useful. Recommended modules: General Relativity, Quantum Field Theory, C++. The evolution of the Universe in terms of the fundamental laws of physics

Stephan Huber Supersymmetry: symmetry between bosons and fermions at the electroweak scale to explain the mass of the Higgs; links to phase transitions and dark matter Extra dimensions/holography: use extra dimensions to explain the nature of the Higgs boson; implications for LHC Electroweak phase transition: electroweak symmetry breaking in the early universe and links to baryogenesis and gravitational waves

Quantum gravity, strong coupling and critical phenomena Daniel Litim can we combine general relativity with quantum mechanics? what’s the trouble with spin-2 degrees of freedom? is metric quantum gravity fundamental? can we combine gravity with the Standard Model? how does metric quantum gravity affects - the unification of couplings? - the running of couplings including the Higgs? - the early universe and inflation? - the late universe and cosmic acceleration? non-perturbative quantum field theory what can we learn about strongly coupled systems - critical scalar/gauge theories? - critical supersymmetry / -gravity? - non-perturbative gravity? - quantum chromodynamics? development of new continuum methods

Quantum gravity, strong coupling and critical phenomena Daniel Litim can we combine general relativity with quantum mechanics? what’s the trouble with spin-2 degrees of freedom? is metric quantum gravity fundamental? can we combine gravity with the Standard Model? how does metric quantum gravity affects - the unification of couplings? - the running of couplings including the Higgs? - the early universe and inflation? - the late universe and cosmic acceleration? non-perturbative quantum field theory what can we learn about strongly coupled systems - critical scalar/gauge theories? - critical supersymmetry / -gravity? - non-perturbative gravity? - quantum chromodynamics? development of new continuum methods

Veronica Sanz Higgs couplings fits: Higgs mechanism; use data coming from the Large Hadron Collider; constrain new physics, such as Supersymmetry. Holography and Superconductivity: build duality between strongly coupled condensed matter system (cuprate superconductor) and models in more than four dimensions. Tools for Dark Matter: searched in telescopes on Earth, the space station, satellites in orbit, the Large Hadron Collider, underground mine facilities, etc; develop tools to connect these; need good theoretical background and some experience with programming (C++, python).