Events at Physics
Events on Friday, March 11th, 2022
- Theory Seminar (High Energy/Cosmology)
- Gravitational Wave Probes of Axion Rotations Responsible for Dark Matter and Baryon Asymmetry
- Time: 1:00 pm
- Place: Chamberlin 5280
- Speaker: Raymond Co, University of Minnesota
- Abstract: We established a paradigm where the (QCD) axion’s novel cosmological evolution, a rotation in the field space, gives rise to dark matter and the baryon asymmetry. The axion rotations also provide a natural origin for a kination era, where the total energy density is dominated by the kinetic term of the axion field, preceded by an early era of matter domination. We investigate the effects of this cosmological scenario on the spectrum of possible primordial gravitational waves from inflation or cosmic strings and find that the spectrum features a triangular peak. As a result, future gravitational wave observations can probe the viable parameter space of kination, including regions that produce axion dark matter by the kinetic misalignment mechanism or the baryon asymmetry by axiogenesis. Lastly, the axion rotation may also source the cosmic perturbations with an observable amount of non-Gaussianity.
- Host: George Wojcik
- Physics Department Colloquium
- CFS and the new public-private fusion energy landscape
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Robert Mumgaard, CFS Energy
- Abstract: With the successful demonstration of its 20T, full-scale toroidal field model coil in September 2021, Commonwealth Fusion Systems (CFS) is now entering the SPARC Era. Over the next four years, CFS and its partners will build, commission and operate the SPARC net-energy tokamak. In parallel, CFS will demonstrate the fusion technology advances required for the first generation of the ARC commercial fusion power plant, which is due to be commissioned in the early 2030’s.This is motivated by the market requirements of the global clean energy transition, and in particular the requirements for fusion to take its place as an industrial energy concern capable of combating climate change. CFS as a company and fusion as a technology are well positioned to reach these goals. CFS has raised over $2b in private funding to date and built a global network of over 40 partner institutions. CFS' roadmap is highly aligned with the strategic goals identified by the US fusion community and National Academy of Sciences, and is involved in multiple public-private partnerships, including many supported in part by competitive DOE awards. Supported by an ARPA-E award, CFS is building 20T all-HTS end coils for the University of Wisconsin's axisymmetric mirror (or WHAM) experiment, demonstrating the speed and flexibility that private companies can bring to the academic ecosystem. In this talk, CFS’ CEO, Bob Mumgaard, will present an overview of the new public-private fusion landscape, CFS’ current status and position in that landscape, and the open problems and challenges on the path to commercial fusion energy.
- Host: Cary Forest
- Soundswaves: small - medium - large
- Time: 7:30 pm
- Place: H.F. DeLuca Forum, Discovery Building
- Speaker: Brian Rebel and others, UW–Madison Physics and other UW depts
- Abstract: SoundWaves looks at the ideas of size and scale. How can tiny particles of matter have a big effect in our universe? How big is infinity? How can a small branch of economic theory explain behaviors outside the scope of economics? How can a collection of individual musical instruments become one instrument that revolutionized the direction of the music we listen to today? Find out in our first event of 2022.
Featuring: Brian Rebel, physics; Raymond Deneckere, economics; Tullia Dymarz, mathematics; Daniel Grabois, SoundWaves curator, music; and Matthew Endres, music.
This event will be held at the Discovery Building and will also be livestreamed on Zoom.
- Host: WARF