Contact
Name
Sebastian Zell

Position
Former member
Member from October 2022 to September 2024
Research statement
My research based at the interface of particle physics and cosmology revolves around fundamental open problems and their observable implications. I am particularly interested in various aspects of gravity as well as inflation – an early phase of exponential expansion in our Universe. Close connections exist with a range of other topics such as dark matter, thermal effects, quantum coherence, scale symmetry, infrared physics and the mass scales of Nature.
Projects
Research directions:
Cosmology and General Relativity
Phenomenology of elementary particles

Active projects
Non-thermal Dark Matter
Marco Drewes, Yannis Georis, Valentin Weber

We study the production of Dark Matter from non-thermal initial states in the early universe, e.g., in freeze-in scenarios. A focus of the project lies in the computation of thermal corrections.
Scalar Fields in the Early Universe
Mubarak Abdallah, Marco Drewes

We study the nonequilibrium dynamics of scalar fields in the early universe in the framework of the Schwinger-Keldysh formalism. We are interested in several applications, including inflation, reheating, Dark Matter production and the fate of the Higgs field in the early universe.
Publications in IRMP
All my publications on Inspire

Number of publications as IRMP member: 10
Last 5 publications

2024

IRMP-CP3-24-28: No Warm Inflation From Sphaleron Heating With a Vanilla Axion
Zell, Sebastian

[Abstract] [PDF]
Refereed paper. September 12.
IRMP-CP3-24-27: Weyl-invariant Einstein-Cartan gravity: unifying the strong CP and hierarchy puzzles
Karananas, Georgios K. and Shaposhnikov, Mikhail and Zell, Sebastian

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. September 12.
IRMP-CP3-24-07: Consistent particle physics in metric-affine gravity from extended projective symmetry
Barker, Will and Zell, Sebastian

[Abstract] [PDF]
Refereed paper. March 11.

2023

IRMP-CP3-23-78: Non-Polynomial Interactions as a Path Towards a Non-Renormalizable UV-Completion
Shaposhnikov, Mikhail and Zell, Sebastian

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. December 26.
IRMP-CP3-23-75: On Sphaleron Heating in the Presence of Fermions
Drewes, Marco and Zell, Sebastian

[Abstract] [PDF] [Journal] [Dial]
30 pages, 1 figure
Refereed paper. December 22.

More publications