“If no one ever hears it how we gonna learn your song?”

– Emeli Sandé

Here you can find a list of all my publications, with a few lines of summary for most of them. If you want to see the bibliometrics like citations and h-number, or to find the most up to date version, head over to my INSPIRE, ADS, or Google Scholar profiles.

*Papers marked with a dagger † indicate first author or equivalent contribution. Papers marked with an asterisk * are signed alphabetically.*

**< 10 authors**

**[16]** * Q. Decant, J. Heisig, **D. C. Hooper**, L. Lopez-Honorez, *Lyman-α constraints on freeze-in and superWIMPs*, arXiv: 2111.09321

We consider dark matter that only interacts feebly with the standard model, therefore requiring a new production mechanism. We focus on two such mechanisms: freeze-in and superWIMP. We derive the formulas necessary to study the cosmological impact of the resulting dark matter, and implement the phase-space distributions in CLASS. This allows us to constrain the models with Lyman-α and BBN data. We apply our general bounds to a specific coloured t-channel mediator dark matter model.

**[15]** * **D. C. Hooper**, M. Lucca, *Hints of dark matter-neutrino interactions in Lyman-α data*, arXiv: 2110.04024

We study the scenario of dark matter interacting with massive neutrinos using the full Lyman-α likelihood we developed in previous work. We show that the Lyman-α data from MIKE/HIRES prefer non-zero interactions at about 3σ. After careful crosschecks, we investigate the two key features of this scenario that lead to a better fit to the data, highlighting what a model could need to solve the well-known tension between Lyman-α and CMB data.

**[14]** N. Schoeneberg, M. Lucca, **D. C. Hooper**, *Constraining the inflationary* *potential with spectral distortions*, JCAP 03 (2021) 036, arXiv: __2010.07814__

We forecast the sensitivity of future spectral distortion missions to different inflationary parameters, and show that these missions will provide constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders of magnitude. We also introduce the marginalisation over foregrounds we have now added to our previously developed spectral distortions pipeline.

**[13]** * N. Becker, **D. C. Hooper**, F. Kahlhoefer, J. Lesgourgues, N. Schoeneberg, *Cosmological constraints on multi-interacting dark matter*, JCAP 02 (2021) 019, arXiv: 2010.04074

We develop a generic framework within CLASS that allows for one dark matter species to have simultaneous interactions with photons, baryons, and dark radiation. We use this framework to show that the effect of these interactions on the CMB is largely additive, with no clear degeneracies in the parameters. We also show that the combination of dark matter – photons and dark matter – dark radiation interactions can reduce both the S_{8} tension and the H_{0} tension. This is the release paper of CLASS v3.2.

**[12]** S. Heimersheim, N. Schoeneberg, **D. C. Hooper**, J. Lesgourgues, *Cannibalism hinders growth: Cannibal Dark Matter and the S*_{8}* tension*, JCAP 12 (2020) 016, arXiv: __2008.08486__

We consider a scenario where dark matter has cannibalistic number changing processes (3->2), which suppress the growth of structure on small scales. We implement this model in CLASS to study its cosmological implications. We show that this model can accommodate low S_{8} values while remaining compatible with CMB+BAO data, providing a solution to the S_{8} tension.

**[11] **H. Fu, M. Lucca, S. Galli, E. S. Battistelli, **D. C. Hooper**, J. Lesgourgues, N. Schoeneberg**, ***Unlocking the synergy between CMB spectral distortions and anisotropies*, arXiv: __2006.12886__

Using the spectral distortions pipeline we previously developed, we study how constraints and degeneracies between cosmological parameters evolve while varying the proposed sensitivity of spectral distortion experiments. This allows us to address the question of which sensitivity we need for such an experiment in order to improve upon CMB anisotropy constraints.

**[10] ***** **I. Baldes, Q. Decant, **D. C. Hooper**, L. Lopez-Honorez, *Non-cold Dark Matter from Primordial Black Hole Evaporation,* JCAP 08 (2020) 045, arXiv: __2004.14773__

We consider non-cold dark matter produced by the evaporation of primordial black holes, which would only interact gravitationally but could be warm enough to be subject to structure formation constraints. We perform a detailed calculation of the dark matter phase-space distribution, which we then interface with CLASS to extract the corresponding matter power spectrum. By remapping warm dark matter bounds, we are able to derive constraints from Lyman-α data without needing to perform new N-body simulations.

**[9] **†* *M. Lucca, **D. C. Hooper**, *Tensions in the dark: shedding light on Dark Matter – Dark Energy interactions,* Phys. Rev. D 102 (2020) 123502, arXiv: __2002.06127__

We study a model of dark matter – dark energy interactions with a coupling term that is linear in the energy density of the dark energy, which has been proposed to solve the H_{0} tension. We show that when including BAO and Pantheon data, the model does not solve the tension, but can alleviate it. We also find no preference in the data for this model over ΛCDM.

**[8] **M. Lucca, N. Schoeneberg, **D. C. Hooper**, J. Lesgourgues, J. Chluba, *The synergy between CMB spectral distortions and anisotropies,* JCAP 02 (2020) 026, arXiv: 1910.04619

We incorporate the calculation of spectral distortions into the Boltzmann code CLASS, and develop accompanying mock likelihoods for future spectral distortion missions for MontePython. We use this framework to forecast the achievable constraints with such a mission on the ΛCDM parameters, on decaying dark matter, and on evaporating primordial black holes. This is the release paper of CLASS v3.0.

**[7] **N. Schoeneberg, J. Lesgourgues, **D. C. Hooper**, *The BAO+BBN take on the Hubble tension, *JCAP 10 (2019) 029, arXiv: __1907.11594__

The combination of BAO and BBN data can probe the background cosmological history independently of CMB and supernovae data. We use this combination to show that when assuming ΛCDM these two datasets are in 3.2σ tension with the SH0ES measurement of H_{0}. We further show that increasing the radiation density parameter N_{eff} can only reduce the tension down to the 2.6σ level, therefore not fully resolving the tension.

**[6] **†* *M. Archidiacono, **D. C. Hooper**, R. Murgia, S. Bohr, J. Lesgourgues, M. Viel, *Constraining Dark Matter – Dark Radiation interactions with CMB, BAO, and Lyman-α*, JCAP 10 (2019) 055, arXiv: __1907.01496__

We develop a new method to extract information from Lyman-α forests which does not require new N-body simulations, but rather relies on interpolating in a grid of pre-existing simulations. We use this method to constrain several different dark matter – dark radiation interactions, placing stringent bounds on the interaction strength and amount of dark radiation. This is the release paper of CLASS v2.9.

**[5] **† T. Brinckmann, **D. C. Hooper**, M. Archidiacono, J. Lesgourgues, T. Sprenger, *The promising future of a robust cosmological neutrino mass measurement,* JCAP 01 (2019) 059*, *arXiv: __1808.05955__

We forecast the expected sensitivity to the sum of neutrino masses for seven CMB missions or combinations thereupon, five large scale structure experiments, and using four fiducial cosmological models, resulting in a total of 140 different scenarios. We show that a neutrino mass detection from cosmology in the next decade is very likely when using a combination of ground-based and satellite missions.

**Collaboration Papers**

**[4]** * EuCAPT^{1}: R. Alves Batista et al., *EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade, *arXiv: 2110.10074

**[3]** * Planck Collaboration^{2}: Y. Akrami et al., *Planck 2018 results. X. Constraints on inflation, *A&A 641 (2020) A10, arXiv: 1807.06211

**[2] * **CORE Collaboration^{3}: J. Delabrouille et al.,* Exploring Cosmic Origins with CORE: Survey requirements* *and mission design*, JCAP 04 (2018) 014*,* arXiv: 1706.04516

**[1] *** CORE Collaboration^{3}: E. Di Valentino et al., *Exploring Cosmic Origins with CORE: Cosmological Parameters, *JCAP 04 (2018) 017, arXiv: __1612.00021__

^{1}* Contribution to the EuCAPT White Paper: Detailed the constraining power of spectral distortion in probing dark matter models across many different mass ranges*

^{2}* Contribution to the Planck Inflation paper: Worked extensively on the Taylor reconstruction of the inflation potential (sections 5.1-5.3) and on the Axion Monodromy analysis (section 7.4)*

^{3}* Contribution to the CORE collaboration: Performed forecasts for the sensitivity of the CORE mission to the effects of DM annihilation on the CMB*

**Proceedings**

**D. C. Hooper**, *Multi-interacting dark matter in the Boltzmann code CLASS*, **PoS TOOLS2020 (2021) 026**, available here

**Ph.D. Thesis**

**D. C. Hooper**, *Extended Cosmological Probes of Massive Dark Relics*, supervisor: J. Lesgourgues, defended: 9th September 2019 in Aachen, available here