My field of expertise lies somewhere between the cosmology of the early universe, gravitational wave physics, theoretical particle physics and statistics. Throughout the last years, I studied phase transitions in dark sectors, which could be observed as a stochastic gravitational wave background. I also did some pulsar timing array data analysis: Together with my colleagues we could show that secluded dark sector phase transitions cannot account for the recently announced gravitational wave background at nano-Hertz frequencies. In another project, we demonstrated how the signal could instead come from the merger of supermassive primordial black holes.

 

Publications

• Sub-GeV dark matter and nano-Hertz gravitational waves from a classically conformal dark sector. Published in: JCAP 08 (2025) 062 • e-Print: 2502.19478 [hep-ph]. Sowmiya Balan (KIT, Karlsruhe, IKP and KIT, Karlsruhe, TTP), Torsten Bringmann (Oslo U.), Felix Kahlhoefer (KIT, Karlsruhe, IKP and KIT, Karlsruhe, TTP and KIT, Karlsruhe, IAP), Jonas Matuszak (KIT, Karlsruhe, IKP and KIT, Karlsruhe, TTP), Carlo Tasillo (DESY and Uppsala U.)

• Hunting WIMPs with LISA: Correlating dark matter and gravitational wave signals. Published in: JCAP 05 (2024) 065 • e-Print: 2311.06346 [astro-ph.CO]. Torsten Bringmann (Oslo U.), Tomás E. Gonzalo (KIT, Karlsruhe, TTP), Felix Kahlhoefer (KIT, Karlsruhe, TTP), Jonas Matuszak (KIT, Karlsruhe, TTP and RWTH Aachen U.), Carlo Tasillo (DESY) (Nov 10, 2023)

• Do pulsar timing arrays observe merging primordial black holes? e-Print: 2306.17836 [astro-ph.CO]. Paul Frederik Depta (Heidelberg, Max Planck Inst.), Kai Schmidt-Hoberg (DESY), Pedro Schwaller (Mainz U., Inst. Phys. and U. Mainz, PRISMA), Carlo Tasillo (DESY) (Jun 30, 2023)

• Does NANOGrav observe a dark sector phase transition? Published in: JCAP 11 (2023) 053 • e-Print: 2306.09411 [astro-ph.CO]. Torsten Bringmann (Oslo U.), Paul Frederik Depta (Heidelberg, Max Planck Inst.), Thomas Konstandin (DESY), Kai Schmidt-Hoberg (DESY), Carlo Tasillo (DESY) (Jun 15, 2023)

• Turn up the volume: listening to phase transitions in hot dark sectors. Published in: JCAP 02 (2022) 02, 014 • e-Print: 2109.06208 [astro-ph.CO]. Fatih Ertas (RWTH Aachen U.), Felix Kahlhoefer (RWTH Aachen U.), Carlo Tasillo (RWTH Aachen U.) (Sep 13, 2021)

Public code

• TransitionListener.

 

Talks

Invited Talks

• Seminar talk, Oskar Klein center and Nordita, Stockholm University, Sweden: The Nano-Hertz Gravitational Wave Background: Connection to sub-GeV dark matter.
• Seminar talk, IFIC, Valencia, Spain: The Nano-Hertz Gravitational Wave Background: Connection to sub-GeV dark matter.
• Seminar talk, astrophysics group, Uppsala University, Sweden: The Nano-Hertz GW Background: Black holes or Phase Transitions?.
• THEP day, May 2025, Uppsala University, Sweden: Can we hope to find gravitational waves from the early cosmos?.
• Introduction to my science for institute members, February 2025, Uppsala University, Sweden: Exploring the Dark Universe with Gravitational Wave Cosmology.
• Seminar talk, December 2024, IPNP Institute, Charles University Prague, Czech Republic: Exploring the dark universe with gravitational wave backgrounds
• Seminar talk, June 2024, Karlsruhe Institute of Technology, Germany: Exploring new physikcs with pulsar timing arrays
• Seminar talk, March 2024, Oslo University, Norway: Exploring cosmological phase transitions with PTAs.
• Plenary talk as convener at the JENAS workshop, February 2024, Sapienza University, Rome, Italy: Gravitational wave cosmology.
• Seminar talk, October 2023, University of Illinois, Chicago, USA. Exploring new physics with PTAs.
• Seminar talk, October 2023, Fermilab, Batavia, Illinois, USA. Exploring new physics with PTAs.
• Seminar talk, June 2023, TU Dortmund University, Germany. How loud was the dark Big Bang?.
• Seminar talk, March 2023, Universidade Federal de Minas Gerais, Brazil. How loud was the dark Big Bang?.
• Seminar talk, January 2022, Carleton University, Ottawa, Canada: Turn up the volume – Listening to hot dark sector phase transitions.

Conference talks and posters

• DESY theory workshop, September 2025, DESY, Hamburg, Germany. Explaining the PTA signal and dark matter with a conformal dark sector.
• Invisibles conference, August 2025, CERN, Geneva, Switzerland. Sub-GeV dark matter from a dark sector phase transition. The poster won the first prize!
• PLANCK conference, May 2025, Padova, Italy. Explaining the PTA signal and dark matter with a conformal dark sector

• EuCAPT symposium, April 2025, online. Explaining the PTA signal and dark matter with a conformal dark sector. Recording available on YouTube.

• Early universe from home, February 2025, online. Do PTAs observe a dark sector phase transition?. Recording available on YouTube.
• HIGGS 2024 conference, November 2024, Uppsala University, Sweden. The (first) LISA miracle.
• DESY theory workshop 2024, September 2024, Hamburg, Germany. The (first) LISA miracle.
• Invisibles workshop 2024, July 2024, Bologna, Italy. Exploring new physics with pulsar timing arrays: Talk and Poster.
• Quarkonia meet dark matter, March 2024, TU Munich, Germany. Panel discussion and talk: Exploring cosmological phase transitions with PTAs.
• JENAS initiaive, February 2024, Sapienza, Rome, Italy. Exploring new physics with PTAs.
• ISAPP autumn school: Exploring the dark universe, November 2023, Texel, Netherlands. Do pulsar timing arrays observe a dark sector phase transition?.
• Kosmologietag Bielefeld, May 2022, Turn up the volume – Listening to hot dark sector phase transitions.
• DESY Theory Workshop, September 2021, DESY Hamburg: Turn up the volume – Listening to hot dark sector phase transitions.

 

Teaching and Outreach

Lectures and courses tought

• Cusanuswerk 2025, Münster, “Kernspalterei” Akademie: Von der Kuh zum Quark.
• Master course on advanced particle physics: Two guest lectures on gravitational waves from first-order phase transitions in the early universe.
• Deutsche SchülerAkademie 2025, Roßleben, “Der Urknall – Von Schwarzen Löchern, Gravitationswellen und dem tiefsten Ton des Universums”: Two weeks with 5h/day lectures and coursework on cosmology and gravitational waves. Taught together with Simon Schwarz.
• Deutsche SchülerAkademie 2024, Wittgenstein, “Big Bang Maths – Die Mathematik des frühen Universums”: Two weeks with 5h/day lectures and coursework on cosmology and gravitational waves. Taught together with Simon Schwarz.
• Deutsche SchülerAkademie 2023, Torgelow, “Big Bang Maths – Die Mathematik des frühen Universums”: Two weeks with 5h/day lectures and coursework on cosmology and dark matter. Taught together with Simon Schwarz.

Tutoring

• Winter term 2018/19, Theoretical Physics IV (Statistical physics), RWTH Aachen University.
• Summer term 2018, Physics IV (Quantum mechanics), TU Dortmund University.
• Winter term 2017/18, Physics III (Analytical mechanics and optics), TU Dortmund University.
• Summer term 2017, Physics II (Electrodynamics and special relativity), TU Dortmund University.
• Winter term 2016/17, Physics I (Classical mechanics and thermodynamics), TU Dortmund University.

 

University requirements

PhD thesis

• PhD defense, October 2024, DESY Hamburg: Exploring the dark universe with gravitational wave backgrounds.
• PhD thesis, August 2024, DESY Hamburg: Exploring the dark universe with gravitational wave backgrounds.

Master thesis

• Master colloquium, June 2021, RWTH Aachen University: Listening to hot dark sector phase transiitons.
• Master thesis, May 2021, RWTH Aachen University: Listening to hot dark sector phase transiitons.

Coursework at Perugia University

• Talk on the proton stability in GUTs, October 2019, Università degli Studi di Perugia: Proton stability as a probe of grand unified theories.
• Talk on natural SUSY Higgs bosons, January 2020, Università degli Studi di Perugia: A natural SUSY Higgs near 125 GeV.

Bachelor thesis

• Bachelor colloquium, July 2018, TU Dortmund University: Freeze-In Production of sterile Neutrino Dark Matter.
• Bachelor thesis, July 2018, TU Dortmund University: Freeze-In Production of sterile Neutrino Dark Matter.