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Higher-order Skyrme hair of black holes

AbstractHigher-order derivative terms are considered as replacement for the Skyrme term in an Einstein-Skyrme-like model in order to pinpoint which properties are necessary for a black hole to possess stable static scalar hair. We find two new models able to support stable black hole hair in the limit of the Skyrme term being turned off. They contain 8 and 12 derivatives...

Self-consistent large-N analytical solutions of inhomogeneous condensates in quantum ℂPN − 1 model

We give, for the first time, self-consistent large-N analytical solutions of inhomogeneous condensates in the quantum ℂPN − 1 model in the large-N limit. We find a map from a set of gap equations of the ℂPN − 1 model to those of the Gross-Neveu (GN) model (or the gap equation and the Bogoliubov-de Gennes equation), which enables us to find the self-consistent solutions. We find...

Ghostbusters in f (R) supergravity

Abstract f (R) supergravity is known to contain a ghost mode associated with higher-derivative terms if it contains R n with n greater than two. We remove the ghost in f (R) supergravity by introducing auxiliary gauge field to absorb the ghost. We dub this method as the ghostbuster mechanism [1]. We show that the mechanism removes the ghost super-multiplet but also terms...

The effective action of a BPS Alice string

Recently a BPS Alice string has been found in a \(U(1)\times SO(3)\) gauge theory coupled with three charged complex scalar fields in the triplet representation (in JHEP 1709:046 arXiv:​1703.​08971 [hep-th], 2017). It is a half BPS state preserving a half of the supercharges when embedded into a supersymmetric gauge theory. In this paper, we study zero modes of a BPS Alice string...

BPS Alice strings

When a charged particle encircles around an Alice string, it changes the sign of the electric charge. In this paper we find a BPS-saturated Alice string in U(1)×SO(3) gauge theory with charged complex scalar fields belonging to the vector representation. After performing BPS completion we solve the BPS equations numerically. We further embed the Alice string into an \( \mathcal{N...

A higher-order Skyrme model

We propose a higher-order Skyrme model with derivative terms of eighth, tenth and twelfth order. Our construction yields simple and easy-to-interpret higher-order Lagrangians. We first show that a Skyrmion with higher-order terms proposed by Marleau has an instability in the form of a baby-Skyrmion string, while the static energies of our construction are positive definite...

Some exact Bradlow vortex solutions

We consider the Bradlow equation for vortices which was recently found by Manton and find a two-parameter class of analytic solutions in closed form on nontrivial geometries with non-constant curvature. The general solution to our class of metrics is given by a hypergeometric function and the area of the vortex domain by the Gaussian hypergeometric function.

Ghost-free vector superfield actions in supersymmetric higher-derivative theories

We systematically construct ghost-free higher-derivative actions of Abelian vector supermultiplets in four-dimensional \( \mathcal{N}=1 \) global supersymmetric theories. After giving a simple example which illustrates that a naive introduction of a higher-derivative term gives rise to a ghost, we discuss possible building blocks for a ghost-free action and explicitly show that...

Fractional instantons and bions in the principal chiral model on \( {\mathrm{\mathbb{R}}}^2\times {S}^1 \) with twisted boundary conditions

Bions are multiple fractional instanton configurations with zero instanton charge playing important roles in quantum field theories on a compactified space with a twisted boundary condition. We classify fractional instantons and bions in the SU(N) principal chiral model on \( {\mathrm{\mathbb{R}}}^2\times {S}^1 \) with twisted boundary conditions. We find that fractional...

Topological solitons in the supersymmetric Skyrme model

A supersymmetric extension of the Skyrme model was obtained recently, which consists of only the Skyrme term in the Nambu-Goldstone (pion) sector complemented by the same number of quasi-Nambu-Goldstone bosons. Scherk-Schwarz dimensional reduction yields a kinetic term in three or lower dimensions and a potential term in two dimensions, preserving supersymmetry. Euclidean...

Semilocal fractional instantons

We find semi-local fractional instantons of codimension four in Abelian and non-Abelian gauge theories coupled with scalar fields and the corresponding \( \mathbb{C}{P}^{N-1} \) and Grassmann sigma models at strong gauge coupling. They are 1/4 BPS states in super-symmetric theories with eight supercharges, carry fractional (half) instanton charges characterized by the fourth...

Fractional instantons and bions in the O(N) model with twisted boundary conditions

Recently, multiple fractional instanton configurations with zero instanton charge, called bions, have been revealed to play important roles in quantum field theories on compactified spacetime. In two dimensions, fractional instantons and bions have been extensively studied in the ℂP N−1 model and the Grassmann sigma model on ℝ1 × S 1 with the ℤ N symmetric twisted boundary...

Stabilizing semilocal strings by polarization

Semilocal strings are vortices in the extended Abelian-Higgs model with two complex Higgs scalar fields among which a global SU(2) symmetry acts. They are known to be stable (unstable against expansion) in type-I (II) superconductors, in which gauge field is heavier (lighter) than the Higgs scalar field. In this paper, we find that vortices can be stabilized in the whole...

Ghostbusters in higher derivative supersymmetric theories: who is afraid of propagating auxiliary fields?

We present for the first time a ghost-free higher-derivative chiral model with a propagating auxiliary F-term field (highest component of the chiral multiplet). We obtain this model by removing a ghost in a higher derivative chiral model, with Higgsing it in terms of an auxiliary vector superfield. Depending on the sign of the quadratic derivative term of the chiral superfield...

Instantons in Lifshitz field theories

BPS instantons are discussed in Lifshitz-type anisotropic field theories. We consider generalizations of the sigma model/Yang-Mills instantons in renormalizable higher dimensional models with the classical Lifshitz scaling invariance. In each model, BPS instanton equation takes the form of the gradient flow equations for “the superpotential” defining “the detailed balance...

Non-BPS exact solutions and their relation to bions in ℂ P N − 1 models

We investigate non-BPS exact solutions in ℂ P N − 1 sigma models on ℝ 1 × S 1 with twisted boundary conditions, by using the Din-Zakrzewski projection method. We focus on the relation of the non-BPS solutions to the ansatz of multi-instanton (bion)configurations and discuss their significance in the context of the resurgence theory. We find that the transition between seemingly...

A supersymmetric Skyrme model

Construction of a supersymmetric extension of the Skyrme term was a long-standing problem because of the auxiliary field problem; that is, the auxiliary field may propagate and cannot be eliminated, and the problem of having fourth-order time derivative terms. In this paper, we construct for the first time a supersymmetric extension of the Skyrme term in four spacetime dimensions...

Gravitating BPS Skyrmions

The BPS Skyrme model has many exact analytic solutions in flat space. We generalize the model to a curved space or spacetime and find that the solutions can only be BPS for a constant time-time component of the metric tensor. We find exact solutions on the curved spaces: a 3-sphere and a 3-hyperboloid; and we further find an analytic gravitating Skyrmion on the 3-sphere. For the...

Resurgence in sine-Gordon quantum mechanics: exact agreement between multi-instantons and uniform WKB

We compute multi-instanton amplitudes in the sine-Gordon quantum mechanics (periodic cosine potential) by integrating out quasi-moduli parameters corresponding to separations of instantons and anti-instantons. We propose an extension of Bogomolnyi-Zinn-Justin prescription for multi-instanton configurations and an appropriate subtraction scheme. We obtain the multi-instanton...

Kelvin modes as Nambu–Goldstone modes along superfluid vortices and relativistic strings: Finite volume size effects

Michikazu Kobayashi 1 Muneto Nitta 0 Subject Index 0 Department of Physics, and Research and Education Center for Natural Sciences, Keio University , Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521