8 papers
Strongly Coupled Sectors in Inflation: Gapped Theories of Unparticles
Yikun Jiang, Guilherme L. Pimentel, Chen Yang
We consider a novel scenario for a strongly coupled spectator sector during inflation, that of a higher dimensional conformal field theory with large anomalous dimensions -- ``unpa…
Searching for Unparticles with the Cosmic Microwave Background
Oliver H. E. Philcox, Guilherme L. Pimentel, Chen Yang
Multi-field models of inflation typically assume that interactions between particles can be treated perturbatively. Strongly-coupled models provide an intriguing alternative and ma…
Inflationary phase transitions in the early Universe: A Bayesian study with space-based gravitational-wave detectors
Qingyuan Liang, Chen Yang, Haipeng An +1
Inflationary phase transitions can generate a stochastic gravitational-wave background that probes primordial physics. We study the detectability and parameter reconstruction of su…
Strongly Coupled Sectors in Inflation: Gapless Theories and Unparticles
Guilherme L. Pimentel, Chen Yang
We compute correlation functions of the primordial density perturbations when they couple to a gapless, strongly coupled sector of spectator fields -- ``unparticles" -- during infl…
Gravitational Waves and Primordial Black Holes produced by Dark Meta Stable Vacuum Decay
Haipeng An, Tingyu Li, Chen Yang
Inspired by string theory and cosmological constant problem, it is plausible that the Universe's vacuum structure is characterized by a landscape of metastable vacua. The existence…
Dark Walker in the Early Universe: A Strongly Coupled Sector Model
Chen Yang
We explore the phenomenology of the ``Dark Walker'' -- an theory with eight flavors of massless fundamental fermions in the dark sector. During inflation, its walkin…