Related papers: On the Anomalous Discrete Symmetry
Utilizing results on the cosmology of anomalous discrete symmetries we show that models of spontaneous CP violation can in principle avoid the domain wall problem first pointed out by Zel'dovich, Kobzarev and Okun. A small but nonzero…
We present a new mechanism for solving the strong CP problem using a Z2 discrete symmetry and an anomalous U(1) symmetry. A Z2 symmetry is used so that two gauge groups have the same theta angle. An anomalous U(1) symmetry makes the…
We reconsider a cosmological evolution of domain walls produced by spontaneous breaking of an approxime discrete symmetry. We show, that domain walls may never collapse even if the standard bound on the vacuum energy asymmetry is satisfied.…
In this note we show that the cosmological domain wall and the de Sitter quantum breaking problems complement each other in theories with discrete symmetries that are spontaneously broken at low energies. Either the symmetry is exact and…
In ordinary QCD with light, degenerate, fundamental flavors, $CP$ symmetry is spontaneously broken at $\theta=\pi$, and domain wall solutions connecting the vacua can be constructed in chiral perturbation theory. In some cases the breaking…
Symmetries in Quantum Field Theory may have 't Hooft anomalies. If the symmetry is unbroken in the vacuum, the anomaly implies a nontrivial low-energy limit, such as gapless modes or a topological field theory. If the symmetry is…
The QCD axion needs not be an exact pseudoscalar for solving the strong CP problem. Its imperfectness can play a profound role cosmologically. We propose effective operators, where the Peccei-Quinn field linearly couples to Standard Model…
Discrete flavor symmetry is often introduced for explaining quark/lepton masses and mixings. However, its spontaneous breaking leads to the appearance of domain walls, which is problematic for cosmology. We consider a possibility that the…
I propose a variant invisible axion model of spontaneous CP violation at the electroweak scale without CP domain wall and `strong CP' problems. Both large size QCD and small size non-QCD instantons break CP and Peccei-Quinn symmetries, and…
We study the dynamics of domain walls in a double-field model in which the U(1) symmetry is broken both spontaneously and explicitly. The global U(1) symmetry of the system is restored when the symmetry breaking parameter $\epsilon$ is set…
Discrete symmetries are widely imposed in particle theories. It is well-known that the spontaneous breaking of discrete symmetries leads to domain walls. Current studies of domain walls have focused on those from the spontaneous breaking of…
I rebuild a conventional two-Higgs doublet model by relaxing the spontaneous CP violation and considering approximate global U(1) family symmetries. So that the domain-wall problem does not explicitly arise at the weak scale, but CP…
The Two Higgs Doublet Model (2HDM) with spontaneously broken $Z_2$ symmetry predicts a production of domain walls at the electroweak scale. We derive cosmological constraints on model parameters for both Type-I and Type-II 2HDMs from the…
We present a complete classification of domain wall solutions in the two-Higgs Doublet Model (2HDM) with a global $\mathbb{Z}_2$ symmetry, categorised as superconducting, CP-violating, or neither, depending on the scalar particle masses and…
Discrete R symmetries are interesting from a variety of points of view. They raise the specter, however, of domain walls, which may be cosmologically problematic. In this note, we describe some of the issues. In many schemes for…
We study the cosmology of the Supersymmetric Standard Model augmented by a gauge singlet to solve the $\mu$-problem and describe the evolution of the domain walls which are created during electroweak symmetry breaking due to the discrete…
We construct a one-dimensional local spin Hamiltonian with an intrinsically non-local, and therefore anomalous, global $\mathbb{Z}_2$ symmetry. The model is closely related to the quantum Ising model in a transverse magnetic field, and…
We propose two novel solutions to the domain wall problem of the QCD axion by introducing a massless or light axion that also couples to gluons. The first solution applies when the new axion forms strings after inflation. Due to its mixing…
The Two Higgs Doublet Model predicts the emergence of 3 distinct domain wall solutions arising from the breaking of 3 accidental global symmetries, $Z_2$, CP1 and CP2, at the electroweak scale for specific choices of the model parameters.…
The QCD axion with $f_a$ at an intermediate scale, 10**9-10**12 GeV, seems in conflict with the gravity spoil of global symmetries and may face the axionic domain wall problem. We point out that the string compactifications with an…