Theory Division

From critical phenomena to quantum gravity, conformal field theories describe the universal scale-invariant structures that lie at the heart of theoretical physics. The conformal bootstrap is the powerful idea, dating back to the 70’s, that one can use fundamental consistency conditions to constrain, solve, and map out the space of conformal field theories. In this... More »

Vortices are non-singular field configurations in $2+1$ dimensions that have finite energy. They have usually been studied in a fixed Minkowski spacetime i.e. without gravity. In this work, we embed vortices in gravity. We find numerically static vortex solutions where the scalar and gauge fields have a non-singular profile under Einstein gravity in an AdS$_3$ background.... More »

The LHCb detector is a dedicated flavour physics detector at the LHC, instrumented in the forward region and optimised for the study of B and D hadron decays. However, due to its unique coverage, it has also made important measurements in a number of other sectors including electroweak and top quark physics. It was also... More »

Galaxy surveys are fundamental tools of cosmology allowing us to measure the geometry and growth of structure in the universe. Using weak gravitational lensing and galaxy clustering from these surveys, we can directly trace the dark matter distribution and infer from this the properties of Dark Energy and Dark Matter. Recent measurements of this kind... More »

The Fermilab Muon g−2 collaboration has recently released its first measurement of (g−2)μ. This result is consistent with previous Brookhaven measurements and together they yield a statistically significant 4.2σ discrepancy with the Standard Model prediction. BSM solutions to (g−2)μ feature light weakly coupled neutral particles (Singlet Scenarios) or heavy strongly coupled charged particles (Electroweak Scenarios). In recent investigations,... More »

Hydrodynamics successfully describes low-energy modes of a wide class of theories including QCD in the strongly-coupled regime. Some of the low energy constants in the hydrodynamic description of QCD, such as shear viscosity, are difficult to obtain from first principles on a classical computer due to the sign problem. One long-standing way to address sign... More »

In extreme astrophysical phenomena like supernova explosions, the large neutrino density can lead to collective flavor oscillations driven by neutrino-neutrino interactions. These phenomena can greatly modify flavor transport in these environments with potentially important consequences for both the explosion mechanism and nucleosynthesis in the ejected material. Even simple models of neutrino-neutrino interactions lead to a... More »

If our apparently four-dimensional spacetime is endowed with compact extra dimensions, our universe may not be entirely stable. It can decay, by the spontaneous nucleation of a “bubble of nothing”: a gravitational instanton that induces a catastrophic annihilation of spacetime. In this talk we discuss the connection between the bubble of nothing and an analogous Coleman-De... More »