I will report on recent advances in the calculation of scattering amplitudes in Quantum Chromodynamics, in particular on new mathematical discoveries and techniques that have made it possible to push their calculations to three loops in perturbation theory.
The cloud-scale physics of star formation and feedback represent the main uncertainties in galaxy formation and evolution simulations. I will present our group's efforts towards overcoming this problem by using empirical constraints on the molecular cloud lifecycle to motivate a new generation of sub-grid models in galaxy simulations. Specifically, I will show how we can use the multi-scale...
In this talk we will elucidate a close connection between black holes and the swampland of quantum gravity.
We explore the observational implications of a model in which primordial black holes (PBHs) with a broad birth mass function ranging in mass from a fraction of a solar mass to ∼106 M⊙, consistent with current observational limits, constitute the dark matter component in the Universe. The formation and evolution of dark matter and baryonic matter in this PBH-ΛCDM~ Universe are presented. In...
Self-interacting dark matter (SIDM) is promising to solve or at least mitigate small-scale problems of cold collisionless dark matter. N-body simulations have proven to be a powerful tool to study SIDM within the astrophysical context. However, it turned out to be difficult to simulate dark matter models that typically scatter about a small angle, for example, light mediator models. We...
The Dark Energy Survey has recently presented cosmological results from weak lensing and galaxy clustering two-point functions using data collected in the first three years of operations. The combination of area (>4000 deg^2) and depth (100 million lensing source galaxies observed) significantly exceeds the previous state of the art, requiring the development of new methodology in several...
On the surface of the early Earth and Earth-like exoplanets ultraviolet (UV) light acts as an important energy source. Particularly, UV light of different wavelength ranges can trigger a variety of photochemical reactions relevant to the molecular origins of life. However, the penetration depth of UV light into natural waters on early Earth and Earth-like exoplanets has remained an open...
Prebiotic lake environments containing ferrocyanide could have fostered origins of life chemistry on the early Earth. Ferrocyanide, coupled with sulfite or sulfide, can participate in an ultraviolet (UV)-driven photoredox cycle to generate solvated electrons, which can reduce cyanide to form all four major building blocks of life: sugars, amino acids, nucleotides, and lipid precursors....
A common thread of the ORIGINS is the presence of ever increasing data volumes both from instruments and simulation that simultaneously promise wealth of scientific insight. This data-intensive era, which often can only be managed in large scientific collaborations, coincides with a particularly interesting, but challenging phase in computing: While Machine Learning, particularly Deep...
In this talk we present how to combine independently trained neural networks to jointly solve novel tasks through Bayesian reasoning. Deep generative networks serve as prior distributions on complex systems and regression/classification networks are used to check whether certain features are present. Bayes Theorem allows us to then solve the inverse problem in terms of the latent variables of...
The quest for dark matter has been puzzling scientists since over a century. The last two decades have seen no less than 20 experiments designed to directly detect dark matter in the local halo. Their sensitivities span over 5 orders of magnitude. In addition to those, hints for the presence of dark matter particles are sought-for in accelerators searches and in cosmic rays. These experiments...
Ligation and recombination of nucleic acids are key reactions required for both self-replication and the emergence of complex sequence information. It is therefore very likely that these reactions played a fundamental role in early stages of biology. We use different ribozyme systems as models to mimic how these reactions might have proceeded under heterogeneous reaction conditions on the...
Determining the connection between the invisible dark matter and the visible distribution of galaxies and gas in the Universe is key not only to understand how galaxy structures form and evolve, but also to use galaxy data to tackle open problems in cosmology like the particle nature of inflation, gravity, dark energy and dark matter. In this talk I will go through a number of recent advances...
We study the effect of density perturbations on the process of first-order phase transitions and gravitational wave production in the early Universe. We are mainly interested in how the distribution of nucleated bubbles is affected by fluctuations in the local temperature. We find that large-scale density fluctuations ($H∗<k∗<\beta$) result in a larger effective bubble size at the time of...
In this project, funded by the Seed Money Grant 2020-2, we have proposed the study of the potential of diamond as cryogenic detectors for the search of light dark matter (DM) candidates. Thanks to its unique cryogenic properties (high Debye temperature and long-lived phonon modes), diamond operated as low temperature calorimeters could reach an energy threshold in the eV range and would allow...
The cryogenic calorimeters developed within the Excellence Cluster ORIGINS are moving the low-energy frontier in astroparticle physics.
The detector technology based on single crystals equipped with tungsten transition-edge-sensors (W-TES), operated at temperatures of about 10mK, allows to reach unprecedented low-energy threshold. Thanks to this technology, the CRESST experiment has achieved...
