arXiv subjects

Mattias E. Thing

Publications and source records attributed to Mattias E. Thing.

4 recordsLinked to original sources

arXiv2024

cp3-bench: A tool for benchmarking symbolic regression algorithms tested with cosmology

We introduce cp3-bench, a tool for comparing symbolic regression algorithms which we make publicly available at https://github.com/CP3-Origins/cp3-bench. Currently, cp3-bench includes 12 symbolic regression algorithms which can be automatically installed as part of cp3-bench. The philosophy behind cp3-bench is that it should be as user-friendly as possible, available in a ready-to-use format, and allow for easy additions of new algorithms and datasets. Our hope is that users of symbolic regression algorithms can use cp3-bench to easily install and compare symbolic regression algorithms to better decide which algorithms to use for their specific tasks at hand. To introduce and motivate the use of cp3-bench we present a benchmark of 12 symbolic regression algorithms applied to 28 datasets representing six different astrophysical setups. Overall, we find that most of the benched algorithms do poorly in the benchmark and suggest possible ways to proceed with developing algorithms that will be better at identifying ground truth expressions for cosmological datasets. Our demonstration benchmark studies the significance of dimensionality of the feature space and precision of datasets. We find both to be highly important for symbolic regression tasks to be successful. On the other hand, we find no indication that inter-dependence of features in datasets is important, i.e. it is not in general a hindrance for symbolic regression algorithms if datasets e.g. contain both $z$ and $H(z)$ as features. Lastly, we find no indication that performance of algorithms on standardized datasets are good indicators of performance on particular astrophysical datasets. This suggests that it is not necessarily prudent to choose symbolic regression algorithms based on their performance on standardized data. A more robust approach is to consider a variety of algorithms, chosen based on the particular task at hand.

astro-ph.IM↗

arXiv2024

Gravitational waves from $\rm{SU(}$$N$$\rm{)/Sp(}$$N$$\rm{)}$ composite Higgs models

We study possible strong first-order electroweak phase transitions in Composite Higgs models and we quantify the part of parameter space that can be probed with future gravitational Wave experiments. We focus on models where the Composite Higgs sector arises from underlying four-dimensional strongly interacting gauge theories with fermions, and where the Standard Model fermion masses are induced via linear mixing terms with composite fermions -- the so-called fermion partial compositeness framework. We perform our analysis for the general class of Composite Higgs models arising from $ N $ Weyl fermions in a pseudo-real representation of the new strongly interacting gauge group that dynamically triggers the global chiral symmetry breaking pattern $\rm{SU(}$$N$$\rm{)}\rightarrow \rm{Sp(}$$N$$\rm{)}$. The minimal model has $ N=4 $ and for $ N>4 $ the models feature complex scalar dark matter candidates arising as pseudo-Nambu-Goldstone bosons. We find a large number of points in the models parameter space which yield strong first-order electroweak phase transitions and identify the most important operators characterizing the strength of the phase transition. Almost all of these points are testable with future GW detectors such as LISA, Taiji, Tianqin, BBO, DECIGO and Ultimate-DECIGO.

hep-ph↗

arXiv2024

Ruling out models of vector dark matter in asymptotically safe quantum gravity

The nature of dark matter is a problem with too many potential solutions. We investigate whether a consistent embedding into quantum gravity can decimate the number of solutions to the dark-matter problem. Concretely, we focus on a hidden sector composed of a gauge field and a charged scalar, with gauge group U(1)$_{\textmd{D}}$ or SU(2)$_\textmd{D}$. The gauge field is the dark matter candidate, if the gauge symmetry is broken spontaneously. Phenomenological constraints on the couplings in this model arise from requiring that the correct dark matter relic density is produced via thermal freeze-out and that recent bounds from direct-detection experiments are respected. We find that the consistent embedding into asymptotically safe quantum gravity gives rise to additional constraints on the couplings at the Planck scale, from which we calculate corresponding constraints at low energy scales. We discover that phenomenological constraints cannot be satisfied simultaneously with theoretical constraints from asymptotically safe quantum gravity, ruling out these dark matter models.

hep-ph↗

arXiv2023

Vector dark matter in supercooled Higgs portal models

We consider extensions of the Standard Model by a hidden sector consisting of a gauge field coupled with a scalar field. Assuming the absence of dimensionful parameters in the tree level potential, radiative symmetry breaking will make the hidden sector gauge field massive and induce the electroweak scale of the Standard Model. We consider separately dark sector gauge groups $U(1)_{\rm{D}}$ and $SU(2)_{\rm{D}}$, and focus on probing the models with a combination of direct detection experiments and gravitational wave observatories. We find that recent dark matter direct detection results significantly constrain the parameter space of the models where they can account for the observed dark matter relic density via freeze-out. The gravitational wave signals originating from strongly first order electroweak phase transition in these models can be probed in future gravitational wave observatories such as the Laser Interferometer Space Antenna. We show how the projected results compliment direct detection experiments and can help probe parameter space near the neutrino floor of direct detection.

hep-ph↗