A very light boson of mass $\mathcal{O}(10^{-22})$ eV may potentially be a viable dark matter (DM) candidate which can avoid phenomenological problems associated with cold DM. Such "fuzzy DM (FDM)" may naturally be an axion with a decay constant $f_a \sim 10^{16} ÷10^{18}$ GeV, and a mass $m_a \sim μ^2/f_a$ with $μ\sim 10^2$ eV. Here we propose a concrete model where $μ$ arises as a dynamical scale from infrared confining dynamics, analogous to QCD. Our model is an alternative to the usual approach of generating $μ$ through string theoretic instanton effects. We outline the features of this scenario that result from various cosmological constraints. We find that those constraints are suggestive of a period of mild of inflation, perhaps from a strong first order phase transition, that reheats the Standard Model (SM) sector only. A typical prediction of our scenario, broadly speaking, is a larger effective number of neutrinos compared to the SM value $N_{\text{eff}} \approx 3$, as inferred from precision measurements of the cosmic microwave background. Some of the new degrees of freedom may be identified as "sterile neutrinos," which may be required to explain certain neutrino oscillation anomalies. Hence, aspects of our scenario could be testable in terrestrial experiments, which is a novelty of our FDM model.
Motivated by the SU(2)$_{\rm CMB}$ modification of the cosmological model $Λ$CDM, we consider isolated fuzzy-dark-matter lumps, made of ultralight axion particles whose masses arise due to distinct SU(2) Yang-Mills scales and the Planck mass $M_P$. In contrast to SU(2)$_{\rm CMB}$, these Yang-Mills theories are in confining phases (zero temperature) throughout most of the Universe's history and associate with the three lepton flavours of the Standard Model of particle physics. As the Universe expands, axionic fuzzy dark matter comprises a three-component fluid which undergoes certain depercola…
We study various entanglement measures in a one-parameter family of three-dimensional, strongly coupled Yang-Mills-Chern-Simons field theories by means of their dual supergravity descriptions. A generic field theory in this family possesses a mass gap but does not have a linear quark-antiquark potential. For the two limiting values of the parameter, the theories flow either to a fixed point or to a confining vacuum in the infrared. We show that entanglement measures are unable to discriminate confining theories from non-confining ones with a mass gap. This lends support on the idea that the ph…
Universal Confining Strings: From Compact QED to the Hadron Spectrum
NiPS Laboratory, INFN and Dipartimento di Fisica e Geologia, University of Perugia（佩鲁贾大学物理与地质学系）；Division of Science, New York University Abu Dhabi（纽约大学阿布扎比分校理学院）；DAMTP University of Cambridge（剑桥大学应用数学与理论物理系）；SwissScientific Technologies SA（瑞士科学技术有限公司）
Study of the Emergence of a Gluon Mass Scale from Center Vortices Using a Wave-Functional Formalism
Universidade Estadual Paulista（圣保罗州立大学）；South-American Institute of Fundamental Research ICTP-SAIFR（南美基础研究所 ICTP-SAIFR）；Universität Tübingen（蒂宾根大学）；Universidade Federal Fluminense（弗鲁米嫩塞联邦大学）
We give an overview of recent progress into the infrared structure of QCD based on the gauge/gravity correspondence and light-front quantization, where the color confining interaction for mesons and baryons is determined by an underlying superconformal algebraic structure. This new approach to hadron physics gives remarkable connections and predictions across the entire mass spectrum of hadrons and also describes the infrared behavior of the strong coupling. More recently, an extensive study of form factors, polarized and unpolarized parton distributions and the sea quark contribution to the n…
