Lecture 1 of Higgs Physics Beyond the SM

• Sven Heinemeyer

Dark matter self-interactions: from halo cores to direct detection

• Boris Betancourt Kamenetskaia (IBS CTPU-CGA)

Self-interactions of dark matter (DM) inevitably give rise to number-changing processes, where n initial DM particles convert into m final states, possibly accompanied by Standard Model particles. Such "n to m" dynamics can strongly affect the density profiles of DM halos, especially in high-density environments such as galactic centers and DM spikes, leading to characteristic modifications relative to collisionless DM. In particular, semi-annihilation processes, where two DM particles convert into one DM particle and one Standard Model particle, not only impact halo structure but also generate a population of boosted DM particles. These boosted components, sourced both locally and from extragalactic halos, open novel avenues for detection. I will discuss how these processes reshape astrophysical expectations for halo profiles and outline their signatures in direct detection and neutrino experiments, highlighting the enhanced sensitivity that such scenarios provide for sub-GeV dark matter.

Discussion

Fun with Calabi-Yau Periods

• Sören Kotlewski (IBS CTPU-PTC)

Period integrals of Calabi-Yau manifolds are a very prominent example of the strong relationship between algebraic geometry and theoretical physics. In physics, these objects might be familiar in the context of String compactifications. As String Theory is anomaly-free only in 10 spacetime dimensions, one needs to compactify six dimensions on some internal space (which in turn has to be Calabi-Yau), to obtain an effective four dimensional theory. This low energy effective field theory is completely determined by the internal geometry - to be precise by the period integrals of the chosen Calabi-Yau manifold. Beside in String Theory, Calabi-Yau manifolds recently appeared in another - unrelated - physical context; the computation of scattering amplitudes, as period integrals of Calabi-Yau manifolds define a set of generating functions for a large class of multi-loop Feynman Integrals. For both applications, it is important to (numerically) compute period integrals up to a high accuracy. Conveniently, this is done by deriving a set of differential equations, called the Picard-Fuchs equations, whose solutions are precisely given by the period integrals. Starting from the string theoretic point of view, I will introduce in this talk the notion of period integrals for three-dimensional Calabi-Yau manifolds and discuss some important properties thereof. Having set the stage, I will present first results of an ongoing research project, which aims towards an efficient computation of Picard-Fuchs ideals for general toric Calabi-Yau manifolds.

Discussion