arXiv subjects

Shouxin Chen

Publications and source records attributed to Shouxin Chen.

At least 19 recordsLinked to original sources

arXiv2025

Vortices for the magnetic Ginzburg-Landau theory in curved space

Since the Ginzburg-Landau theory is concerned with macroscopic phenomena, and gravity affects how objects interact at the macroscopic level. It becomes relevant to study the Ginzburg-Landau theory in curved space, that is, in the presence of gravity. In this paper, some existence theorems are established for the vortex solutions of the magnetic Ginzburg-Landau theory coupled to the Einstein equations. First, when the coupling constant \lambda=1, we get a self-dual structure from the Ginzburg-Landau theory, then a partial differential equation with a gravitational term that has power-type singularities is deduced from the coupled system. To overcome the difficulty arising from the orders of singularities at the vortices, a constraint minimization method and a monotone iteration method are employed. We also show that the quantized flux and total curvature are determined by the number of vortices. Second, when the coupling constant \lambda>0, we use a suitable ansatz to get the radially symmetric case for the magnetic Ginzburg-Landau theory in curved space. The existence of the symmetric vortex solutions are obtained through combining a two-step iterative shooting argument and a fixed-point theorem approach. Some fundamental properties of the solutions are established via applying a series of analysis techniques.

math-ph↗

arXiv2024

Existence of non-Abelian vortices in a coupled 4D-2D quantum field theory

Vortices produce locally concentrated field configurations and are solutions to the nonlinear partial differential equations systems of complicated structures. In this paper, we establish the existence and uniqueness for solutions of the gauged non-Abelian vortices in a coupled 4D-2D quantum field theory by researching the nonlinear elliptic equations systems with exponential terms in $\mathbb{R}^{2}$ using the calculus of variations. In addition, we obtain the asymptotic behavior of the solutions at infinity and the quantized integrals in $\mathbb{R}^{2}$.

math.AP↗

arXiv2024

Twisted vortices in two-component Ginzburg-Landau theory

In this note, a brief introduction to the physical and mathematical background of the two-component Ginzburg-Landau theory is given. From this theory we derive a boundary value problem whose solution can be obtained in part by solving a minimization problem using the technique of variational method, except that two of the eight boundary conditions cannot be satisfied. To overcome the difficulty of recovering the full set of boundary conditions, we employ a variety of methods, including the uniform estimation method and the bounded monotonic theorem, which may be applied to other complicated vortex problems in gauge field theories. The twisted vortex solutions are obtained as energy-minimizing cylindrically symmetric field configurations. We also give the sharp asymptotic estimates for the twisted vortex solutions at the origin and infinity.

math-ph↗

arXiv2024

Multiple cosmic strings in Chern-Simons-Higgs theory with gravity

In this paper, we consider the self-dual equation arising from Abelian Chern-Simons-Higgs theory coupled to the Einstein equations over the plane $\mathbb{R}^2$ and a compact surface $S$. We prove the existence of symmetric topological solutions and non-topological solutions on the plane by using the fixed-point theorem and a shooting method, respectively. A necessary and sufficient condition related to the string number $N$, the Euler characteristic $χ(S)$ of $S$, and the gravitational coupling factor $G$ is given to show the existence of $N$-string solutions over a compact surface.

math-ph↗

arXiv2023

Vortices and strings induced from a generalized Abelian Higgs model

In this note we construct self--dual vortices and cosmic strings from the generalized Abelian Higgs theory. A special model of the theory is of focused interest in which the Higgs potential is a polynomial depending on $m$. When $|m|>0$, we obtain sharp existence theorems for vortices and strings correspond to gravity absence and appearance, respectively over the full plane. In particular, the vortex solution is unique if $m<0$. In order to over the difficulties posed by gravity, we introduce the regularization method when there are at least two distinct points among the set of centers of strings. When all these points coincide, the fixed point theorem works well. A series properties regarding vortices and strings for $|m|>0$ are also established.

math-ph↗

arXiv2023

Cosmic strings in a generalized linear formulation of gauge field theory

In this note we construct self-dual cosmic strings from a gauge field theory with a generalized linear formation of potential energy density. By integrating the Einstein equation, we obtain a nonlinear elliptic equation which is equal with the sources. We prove the existence of a solution in the broken symmetry category on the full plane and the multiple string solutions are valid under a sufficient condition imposed only on the total string number N. The technique of upper-lower solutions and the method of regularization are employed to show the existence of a solution when there are at least two distant string centers. When all the string centers are identical, fixed point theorem are used to study the properties of the nonlinear elliptic equation. Finally, We give the sharp asymptotic estimate for the solution at infinity.

math-ph↗

arXiv2022

Existence of Vortices for Nonlinear Schrödinger Equations

In this paper, we study the existence of vortices for two kinds of nonlinear Schrödinger equations arising from the Bose-Einstein condensates and geometric optics arguments, respectively. For the Gross-Pitaevskii equation from Bose-Einstein condensates arguments, we introduce the weighted Sobolev space on which the corresponding functional is coercive. By using the variational methods, we prove the existence of positive and radially symmetric solutions under different types of boundary condition. And we study another equation arising from geometric optics arguments by constrained minimization method. Furthermore some explicit estimates for the bound of the wave propagation constant are also derived.

math.AP↗

arXiv2022

The Existence of Dyon Solutions for Generalized Weinberg-Salam Model

The generalized Weinberg-Salam model which is presented in a recent study of Kimm, Yoon and Cho, is arising in electroweak theory. In this paper, we prove the existence and asymptotic behaviors at infinity of static and radially symmetric dyon solutions to the boundary-value problem of this model. Moreover, as a by product, the qualitative properties of dyon solutions are also obtained. The methods used here are the extremum principle, the Schauder fixed point theory and the shooting approach depending on one shooting parameter. We provide an effective framework for constructing the dyon solutions in general dimensions and develop the existing results.

math.AP↗

arXiv2020

Dilaton Mass Formulas in a Hairy Binary Black Hole Model

In this note an analytic integration is obtained for the differential equation governing the scalar-field-dependent mass in a hairy binary black hole model, in the context of the Einstein--Maxwell--dilation theory, which gives a closed-form formula-level description of the mass function. We also identify a particular solution which attracts all solutions of the mass-governing equation exponentially rapidly in large-dilaton-field limit.

gr-qc↗

arXiv2019

Domain Wall Solitons Arising in Classical Gauge Field Theories

Domain wall solitons are basic constructs realizing phase transitions in various field-theoretical models and are solutions to some nonlinear ordinary differential equations descending from the corresponding full sets of governing equations in higher dimensions. In this paper, we present a series of domain wall solitons arising in several classical gauge field theory models. In the context of the Abelian gauge field theory, we unveil the surprising result that the solutions may explicitly be constructed, which enriches our knowledge on integrability of the planar Liouville type equations in their one-dimensional limits. In the context of the non-Abelian gauge field theory, we obtain some existence theorems for domain wall solutions arising in the electroweak type theories by developing some methods of calculus of variations formulated as direct and constrained minimization problems over a weighted Sobolev space.

math-ph↗

arXiv2015

Domain Wall Equations, Hessian of Superpotential, and Bogomol'nyi Bounds

An important question concerning the classical solutions of the equations of motion arising in quantum field theories at the BPS critical coupling is whether all finite-energy solutions are necessarily BPS. In this paper we present a study of this basic question in the context of the domain wall equations whose potential is induced from a superpotential so that the ground states are the critical points of the superpotential. We prove that the definiteness of the Hessian of the superpotential suffices to ensure that all finite-energy domain-wall solutions are BPS. We give several examples to show that such a BPS property may fail such that non-BPS solutions exist when the Hessian of the superpotential is indefinite.

hep-th↗

arXiv2015

Friedmann-Lemaitre Cosmologies via Roulettes and Other Analytic Methods

In this work a series of methods are developed for understanding the Friedmann equation when it is beyond the reach of the Chebyshev theorem. First it will be demonstrated that every solution of the Friedmann equation admits a representation as a roulette such that information on the latter may be used to obtain that for the former. Next the Friedmann equation is integrated for a quadratic equation of state and for the Randall--Sundrum II universe, leading to a harvest of a rich collection of new interesting phenomena. Finally an analytic method is used to isolate the asymptotic behavior of the solutions of the Friedmann equation, when the equation of state is of an extended form which renders the integration impossible, and to establish a universal exponential growth law.

gr-qc↗

arXiv2015

Explicit Integration of Friedmann's Equation with Nonlinear Equations of State

This paper is a continuation of our earlier study on the integrability of the Friedmann equations in the light of the Chebyshev theorem. Our main focus will be on a series of important, yet not previously touched, problems when the equation of state for the perfect-fluid universe is nonlinear. These include the generalized Chaplygin gas, two-term energy density, trinomial Friedmann, Born--Infeld, and two-fluid models. We show that some of these may be integrated using Chebyshev's result while other are out of reach by the theorem but may be integrated explicitly by other methods. With the explicit integration, we are able to understand exactly the roles of the physical parameters in various models play in the cosmological evolution. For example, in the Chaplygin gas universe, it is seen that, as far as there is a tiny presence of nonlinear matter, linear matter makes contribution to the dark matter, which becomes significant near the phantom divide line. The Friedmann equations also arise in areas of physics not directly related to cosmology. We provide some examples ranging from geometric optics and central orbits to soap films and the shape of glaciated valleys to which our results may be applied.

gr-qc↗

arXiv2014

Friedmann's Equations in All Dimensions and Chebyshev's Theorem

This short but systematic work demonstrates a link between Chebyshev's theorem and the explicit integration in cosmological time $t$ and conformal time $η$ of the Friedmann equations in all dimensions and with an arbitrary cosmological constant $Λ$. More precisely, it is shown that for spatially flat universes an explicit integration in $t$ may always be carried out, and that, in the non-flat situation and when $Λ$ is zero and the ratio $w$ of the pressure and energy density in the barotropic equation of state of the perfect-fluid universe is rational, an explicit integration may be carried out if and only if the dimension $n$ of space and $w$ obey some specific relations among an infinite family. The situation for explicit integration in $η$ is complementary to that in $t$. More precisely, it is shown in the flat-universe case with $Λ\neq0$ that an explicit integration in $η$ can be carried out if and only if $w$ and $n$ obey similar relations among a well-defined family which we specify, and that, when $Λ=0$, an explicit integration can always be carried out whether the space is flat, closed, or open. We also show that our method may be used to study more realistic cosmological situations when the equation of state is nonlinear.

astro-ph.CO↗

arXiv2014

Exact Kink Solitons in Skyrme Crystals

We present an explicit integration of the kink soliton equation obtained in a recent interesting study of the classical Skyrme model where the field configurations are of a generalized hedgehog form which is of a domain-wall type. We also show that in such a reduced one-dimensional setting the first-order and second-order equations are equivalent. Consequently, in such a context, all finite-energy solitons are BPS type and precisely known.

math-ph↗

arXiv2013

Existence theorems for non-Abelian Chern--Simons--Higgs vortices with flavor

In this paper we establish the existence of vortex solutions for a Chern--Simons--Higgs model with gauge group $SU(N) \times U(1)$ and flavor SU(N), these symmetries ensuring the existence of genuine non-Abelian vortices through a color-flavor locking. Under a suitable ansatz we reduce the problem to a $2\times 2$ system of nonlinear elliptic equations with exponential terms. We study this system over the full plane and over a doubly periodic domain, respectively. For the planar case we use a variational argument to establish the existence result and derive the decay estimates of the solutions. Over the doubly periodic domain we show that the system admits at least two gauge-distinct solutions carrying the same physical energy by using a constrained minimization approach and the mountain-pass theorem. In both cases we get the quantized vortex magnetic fluxes and electric charges.

math.AP↗

arXiv2012

Exact kink solitons in a monopole confinement problem

We explicitly construct all kink solitons arising in the recent study of Auzzi, Bolognesi, and Shifman of a monopole confinement problem in ${\cal N}=2$ supersymmetric QCD. In particular, we show that all finite-energy kink solitons must be BPS.

math-ph↗

arXiv2012

Existence of Multiple Vortices in Supersymmetric Gauge Field Theory

Two sharp existence and uniqueness theorems are presented for solutions of multiple vortices arising in a six-dimensional brane-world supersymmetric gauge field theory under the general gauge symmetry group $G=U(1)\times SU(N)$ and with $N$ Higgs scalar fields in the fundamental representation of $G$. Specifically, when the space of extra dimension is compact so that vortices are hosted in a 2-torus of volume $|\Om|$, the existence of a unique multiple vortex solution representing $n_1,...,n_N$ respectively prescribed vortices arising in the $N$ species of the Higgs fields is established under the explicitly stated necessary and sufficient condition \[ n_i<\frac{g^2v^2}{8πN}|\Om|+\frac{1}{N}(1-\frac{1}{N}[\frac{g}{e}]^2)n,\quad i=1,...,N,] where $e$ and $g$ are the U(1) electromagnetic and SU(N) chromatic coupling constants, $v$ measures the energy scale of broken symmetry, and $n=\sum_{i=1}^N n_i$ is the total vortex number; when the space of extra dimension is the full plane, the existence and uniqueness of an arbitrarily prescribed $n$-vortex solution of finite energy is always ensured. These vortices are governed by a system of nonlinear elliptic equations, which may be reformulated to allow a variational structure. Proofs of existence are then developed using the methods of calculus of variations.

math.AP↗