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Related papers: $\alpha$-Dirac-harmonic maps from closed surfaces

200 papers

We study the existence of harmonic maps and Dirac-harmonic maps from degenerating surfaces to non-positive curved manifold via the scheme of Sacks and Uhlenbeck. By choosing a suitable sequence of $\alpha$-(Dirac-)harmonic maps from a…

Differential Geometry · Mathematics 2021-06-25 Jürgen Jost , Jingyong Zhu

We show the smoothness of weakly Dirac-harmonic maps from a closed spin Riemann surface into stationary Lorentzian manifolds, and obtain a regularity theorem for a class of critical elliptic systems without anti-symmetry structures.

Analysis of PDEs · Mathematics 2020-03-31 Wanjun Ai , Miaomiao Zhu

In this paper, we discuss the general existence theory of Dirac-harmonic maps from closed surfaces via the heat flow for $\alpha$-Dirac-harmonic maps and blow-up analysis. More precisely, given any initial map along which the Dirac operator…

Differential Geometry · Mathematics 2021-03-12 Jürgen Jost , Jingyong Zhu

In 1981, Sacks and Uhlenbeck introduced their famous $\alpha$-energy as a way to approximate the Dirichlet energy and produce harmonic maps from surfaces into Riemannian manifolds. However, the second and third authors together with…

Differential Geometry · Mathematics 2022-06-01 Jasmin Hörter , Tobias Lamm , Mario Micallef

We prove existence results for Dirac-harmonic maps using index theoretical tools. They are mainly interesting if the source manifold has dimension 1 or 2 modulo 8. Our solutions are uncoupled in the sense that the underlying map between the…

Differential Geometry · Mathematics 2015-10-28 Bernd Ammann , Nicolas Ginoux

As a commutative version of the supersymmetric nonlinear sigma model, Dirac-harmonic maps from Riemann surfaces were introduced fifteen years ago. They are critical points of an unbounded conformally invariant functional involving two…

Analysis of PDEs · Mathematics 2025-07-08 Jürgen Jost , Jingyong Zhu

For a homotopy class $[u]$ of maps between a closed Riemannian manifold $M$ and a general manifold $N$, we want to find a Dirac-harmonic map with the map component in the given homotopy class. Most known results require the index to be…

Differential Geometry · Mathematics 2024-12-24 Jürgen Jost , Linlin Sun , Jingyong Zhu

For any $n$-dimensional compact spin Riemannian manifold $M$ with a given spin structure and a spinor bundle $\Sigma M$, and any compact Riemannian manifold $N$, we show an $\epsilon$-regularity theorem for weakly Dirac-harmonic maps . As a…

Analysis of PDEs · Mathematics 2011-02-19 Changyou Wang , Deliang Xu

The first result in this study is a non-existence theorem for $\alpha-$harmonic mappings. Additionally, a direct connection between the $\alpha-$ harmonic and harmonic maps is made possible via conformal deformation. Second, the instability…

Differential Geometry · Mathematics 2022-08-26 Seyed Mehdi Kazemi Torbaghan , Keyvan Salehi

We study Dirac-harmonic maps from surfaces to manifolds with torsion, which is motivated from the superstring action considered in theoretical physics. We discuss analytic and geometric properties of such maps and outline an existence…

Differential Geometry · Mathematics 2016-05-10 Volker Branding

We establish the regularity theory for certain critical elliptic systems with an anti-symmetric structure under inhomogeneous Neumann and Dirichlet boundary constraints. As applications, we prove full regularity and smooth estimates at the…

Differential Geometry · Mathematics 2015-11-20 Ben Sharp , Miaomiao Zhu

Critical points of approximations of the Dirichlet energy \`{a} la Sacks-Uhlenbeck are known to converge to harmonic maps in a suitable sense. However, we show that not every harmonic map can be approximated by critical points of such…

Differential Geometry · Mathematics 2015-08-06 Tobias Lamm , Andrea Malchiodi , Mario Micallef

We study the evolution equations for a regularized version of Dirac-harmonic maps from closed Riemannian surfaces. We establish the existence of a global weak solution for the regularized problem, which is smooth away from finitely many…

Differential Geometry · Mathematics 2020-07-06 Volker Branding

In this paper we consider approximations introduced by Sacks-Uhlenbeck of the harmonic energy for maps from $S^2$ into $S^2$. We continue the analysis in [6] about limits of $\alpha$-harmonic maps with uniformly bounded energy. Using a…

Differential Geometry · Mathematics 2021-05-19 Tobias Lamm , Andrea Malchiodi , Mario Micallef

We study a functional, whose critical points couple Dirac-harmonic maps from surfaces with a two form. The critical points can be interpreted as coupling the prescribed mean curvature equation to spinor fields. On the other hand, this…

Differential Geometry · Mathematics 2015-10-15 Volker Branding

We study several geometric and analytic aspects of Dirac-harmonic maps with curvature term from closed Riemannian surfaces.

Differential Geometry · Mathematics 2015-12-01 Volker Branding

We study a new set of coupled field equations motivated by the non-linear supersymmetric sigma model of quantum field theory. These equations couple a map into a Riemannian manifold controlled by a harmonic map like action with a spinor…

Differential Geometry · Mathematics 2007-05-23 Qun Chen , Juergen Jost , Guofang Wang , Jiayu Li

For $n\ge 3$, let $\Omega$ be a bounded domain in $R^n$ and $N$ be a compact Riemannian manifold in $R^L$ without boundary. Suppose that $u_n\in W^{1,n}(\Omega,N)$ are the Palais-Smale sequences of the Dirichlet $n$-energy functional and…

Analysis of PDEs · Mathematics 2015-06-26 Changyou Wang

In this paper, we first study the $\alpha-$energy functional, Euler-Lagrange operator and $\alpha$-stress energy tensor. Second, it is shown that the critical points of $\alpha-$ energy functional are explicitly related to harmonic maps…

Differential Geometry · Mathematics 2022-08-18 Seyed Mehdi Kazemi Torbaghan , Keyvan Salehi , Salman Babayi

Adapting \cite{strz3}, we define generalized $p$-harmonic maps into Riemannian homogeneous targets, a notion of solutions not belonging to the energy space. Restricting our attention to the subcritical range $p$ greater than the domain…

Analysis of PDEs · Mathematics 2025-06-23 Gianmichele Di Matteo , Tobias Lamm
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