The dark dimensions of the Universe

by Prof. Ignatios Antoniadis (LPTHE Sorbonne Université and Chulalongkorn University)

Thursday 15 Oct 2026, 11:00 → 12:00 Asia/Shanghai

Tsung-Dao Lee Institute/N6F-N600 - Lecture Room (Tsung-Dao Lee Institute)

Abstract: 

Extra dimensions are an important ingredient of theories of quantum gravity such as string theory. If their size is large, gravity becomes strong at energies lower than the Planck scale with important theoretical and observational consequences. I will argue on the possibility that extra dimensions acquire large size by higher dimensional inflation, relating the weakness of the actual gravitational force to the size of the observable universe. Although this can be realised for any number of extra dimensions, the requirement of (approximate) flat power spectrum of primordial density fluctuations consistent with present observations makes this simple proposal possible only for one or two extra dimensions at around the micron scale. This scenario can then be nicely combined with the Dark Dimension proposal for the cosmological constant, stemmed from the large distance swampland conjecture. I will describe its main phenomenological consequences in particle physics and cosmology.

Biography: 

Prof. Ignatios Antoniadis holds a Doctorat d’État from École Polytechnique and a PhD from École Normale Supérieure, both in Paris. He has held positions at research institutions including CERN, CNRS, and Sorbonne University, and is currently a Distinguished Visiting Professor at the Tsung-Dao Lee Institute, Shanghai Jiao Tong University. He has also served as a visiting professor at Harvard University and as a Member of the Institute for Advanced Study in Princeton. His research focuses on quantum field theory, particle physics, string theory, and cosmology. He has published over 320 scientific articles, with more than 30,000 citations and an h-index of 83. His honors include an ERC Advanced Grant and the CNRS Silver Medal.

Alternative online link：https://meeting.tencent.com/dm/OlDWH5b1jNIs

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