Události

In this talk, we present an amusing observation that primordial gravitational waves, if ever observed, can be used to bound the hidden field content of the universe. This is because a large number of hidden fields can resum to potentially observable logarithmic runnings for the graviton two-point function in the context of single field inflation, courtesy of a `large N' expansion. This allows one to translate ever more precise bounds on the tensor to scalar consistency relation into bounds on the hidden field content of the universe, with potential implications for phenomenological...

    Topological insulators (TI) belong to the phase category which goes beyond the theory of spontaneous symmetry breaking, well describing the classical phases. TI were initially theoretically predicted for materials with strong spin-orbit interactions that lead to the reversal of the sequence of the valence band and the conduction band. Consequently, these materials behave as insulators in the volume while their surfaces host metallic states. The metallic states have an unusual spin structure, with the electron spin locked to its momentum, described by the Dirac-type...

Abstract> Perovskite oxides are promising materials in applications ranging from solid oxide fuel cells to catalysts, yet their surface chemistry is surprisingly poorly understood at the atomic level. The present talk will discuss recent results of combined theoretical - density functional theory (DFT) - and experimental - mostly low-temperature scanning tunnelling microscopy (STM) – studies on ruthenate surfaces and focus on:
• High chemical activity: CO on Sr₃Ru₂O₇(001) (SRO)
• Dissociated but not separated: H₂O on...