Related papers: The Holographic QCD Axion in Five Dimensions
A general class of holographic theories with a nontrivial $\theta$-angle are analyzed. The instanton density operator is dual to a bulk axion field. We calculate the ground-state solutions with nontrivial source, $a_{UV}$, for the axion,…
We construct a localized state of a scalar field in 3D spin-3 gravity. 3D spin-3 gravity is thought to be holographically dual to W$_3$ extended CFT on a boundary at infinity. It is known that while W$_3$ algebra is a non-linear algebra, in…
We discuss how a dominant tetraquark component of the lightest scalar mesons may emerge in AdS/QCD gravity duals. In particular, we show that the exceptionally strong binding required to render the tetraquark ground state lighter than the…
We present a new mechanism to deplete the energy density of the QCD axion, making decay constants as high as $f_a \simeq 10^{17}\,\rm{GeV}$ viable for generic initial conditions. In our setup, the axion couples to a massless dark photon…
Motivated UV frameworks generically predict the existence of multiple axion fields. Their interplay gives rise to novel collective phenomena - including level crossings and the formation of string bundles - which modify the predicted mass…
Extended QCD (XQCD) proposed by Kaplan [1] is an interesting reformulation of QCD with additional bosonic auxiliary fields. While its partition function is kept exactly the same as that of original QCD, XQCD naturally contains properties of…
The $(3+1)$-dimensional evolution of an inhomogeneous axion field configuration around the QCD epoch is studied numerically, including important non-linear effects due to the attractive self-interaction. It is found that axion perturbations…
The axial-vector form factor of the nucleons is considered in the framework of hard-wall model of holographic QCD. A new interaction term between the bulk gauge and matter fields was included into the interaction Lagrangian. We obtain the…
The finite-curvature phase diagram of IHQCD, a bottom-up holographic model for large $N_c$ non-supersymmetric YM$_4$, is investigated. This holographic theory belongs to a class of Einstein-Dilaton theories that exhibit no scaling in the…
We show that the QCD axion couples to the electromagnetic kinetic term at one loop. The result is that if axions make up dark matter, they induce temporal variation of the fine structure constant $\alpha$, which is severely constrained. We…
We apply the quantum renormalization group to construct a holographic dual for the U(N) vector model for complex bosons defined on a lattice. The bulk geometry becomes dynamical as the hopping amplitudes which determine connectivity of…
The QCD axion has important connections to early universe cosmology. For example, it is often said that isocurvature limits rule out a combination of high axion decay constant, $f_a$, and high inflationary Hubble scale, $H_I$. High scales…
We present new results on the equation of state and transition line of hot and dense strongly interacting QCD matter, obtained from a bottom-up Einstein-Maxwell-Dilaton holographic model. We considerably expand the previous coverage in…
We highlight general issues associated with quality and naturalness problems in theories of light QCD-axions, axion-like particles, and relaxions. We show the presence of Planck-suppressed operators generically lead to scalar coupling of…
Thermodynamics and transport are investigated in a holographic QCD model that extends the Einstein--Maxwell--Dilaton framework by incorporating Gauss--Bonnet corrections. Model parameters are fixed using state-of-the-art lattice QCD…
In holographic models of cosmology based on the (A)dS/CFT correspondence, conformal symmetry is implicit in the dual description of the Universe. Generically, however, one cannot expect the (broken) conformal invariance in the cosmic…
In the holographic correspondence of quantum gravity, a global onsite symmetry at the boundary generally translates to a local gauge symmetry in the bulk. We describe one way how the global boundary onsite symmetries can be gauged within…
The supersymmetric QCD corrections to the hadronic width of a heavy charged Higgs boson, basically dominated by the top-quark decay mode $H^{+}\rightarrow t \bar{b}$, are evaluated at ${\cal O}(\alpha_s)$ within the MSSM and compared with…
The topological susceptibility of the QCD vacuum provides an understanding of $\theta$-vacua as vacua of a Chern-Simons gauge theory. In this way, it gives an immediate proof of the physicality of the boundary $\theta$-term. This makes the…
The simplest version of the dynamical holographic QCD model is described by adding the KKSS model action on a dilaton-graviton coupled background, in which the AdS$_5$ metric is deformed by the gluon condensation and further deformed by the…