arXiv research

One-harmonic maps from a curved surface to hyperbolic plane have specific interior properties.

Study on harmonicity of maps between different types of almost contact metric manifolds.

Notes on harmonic maps between manifolds, existence and regularity covered.

Study improves regularity estimates for harmonic maps into ellipsoids.

Survey on harmonic maps in non-smooth spaces, focusing on rigidity.

We define a transformation on harmonic maps from a Riemann surface into the 2-sphere which depends on a complex parameter, the so-called mu-Darboux transformation. In the case when the harmonic map N is the Gauss map of a constant mean curvature surface f and the parameter is real, the mu-Darboux transformation of -N i…

In this paper, we give some rigidity results for both harmonic and pseudoharmonic maps from CR manifolds into Riemannian manifolds or Kahler manifolds. Some basicity, pluriharmonicity and Siu-Sampson type results are established for both harmonic maps and pseudoharmonic maps.

Study on harmonic maps on weighted Riemannian foliations.

We study the topology of a complete asymptotically hyperbolic Einstein manifold such that its conformal boundary has positive Yamabe invariant. We proved that all maps from such manifold into any nonpositively curved manifold are homotopically trivial. Our proof is based on a Bochner type argument on harmonic maps.

Study on harmonic maps in special geometric spaces.

Analyzes harmonic and biharmonic maps from gradient Ricci solitons.

Harmonic mappings into Teichmuller spaces appear in the study of manifolds which are fibrations whose fibers are Riemann surfaces. In this article we will study the existence and uniquenesses questions of harmonic mappings into Teichmuller spaces, as well as some local and global behavior of the harmonic images induced…

Study on harmonic maps between cones, linking degrees to graph Laplacian eigenvalues.

We show that many surfaces in $\R^{N^2-1}$ can be generated by harmonic maps of $S^2\to CP^{N-1}$. These surfaces are based on the projectors in $CP^{N-1}$ which describe maps of $S^2\to CP^{N-1}$. In the case when these maps form the Veronese sequence all the surfaces have constant curvature.

The paper constructs biharmonic maps between spheres using polynomial maps.

We give conditions on the Lee vector field of an almost Hermitian manifold such that any holomorphic map from this manifold into a (1,2)-symplectic manifold must satisfy the fourth-order condition of being biharmonic, hence generalizing the Lichnerowicz theorem on harmonic maps. These third-order non-linear conditions …

Harmonic maps from complex plane to hyperbolic space constructed using heat flow.

Study on harmonic maps from surfaces with energy bounds and neck domains.

Research proves limits on harmonic map orders into Euclidean buildings.

This paper is devoted to the study of the global properties of harmonically immersed Riemann surfaces in $\mathbb{R}^3.$ We focus on the geometry of complete harmonic immersions with quasiconformal Gauss map, and in particular, of those with finite total curvature. We pay special attention to the construction of new ex…

The study establishes uncertainty principles on harmonic manifolds of rank one.

Study on harmonic maps from surfaces to homogeneous spaces, focusing on bubble formation and geometric constraints.

In this paper, we will prove a result of nonexistence on harmonic diffeomorphisms between punctured spaces. In particular, we will given an elementary proof to the nonexistence of rotationally symmetric harmonic diffeomorphisms from the punctured Euclidean space onto the punctured hyperbolic space.

Biharmonic maps are generalizations of harmonic maps. A well-known result of Eells and Wood on harmonic maps between surfaces shows that there exists no harmonic map from a torus into a sphere (whatever the metrics chosen) in the homotopy class of maps of Brower degree $\pm 1$. It would be interesting to know if there …

Harmonic maps are described using Jacobi elliptic functions.

This is primarily a survey of the developments in the theory of harmonic maps of finite uniton number (or unitons) which have taken place since the introduction of extended solutions by Uhlenbeck. Such maps include all harmonic maps from the two-sphere to a compact Lie group or symmetric space. Extended solutions are e…

Survey of Willmore surfaces in spheres using DPW method.

Study shows only rotations can be approximated by Ginzburg-Landau critical points.

We classify all harmonic maps with finite uniton number from a Riemann surface into an arbitrary compact simple Lie group $G$, whether $G$ has trivial centre or not, in terms of certain pieces of the Bruhat decomposition of the group $Ω_\mathrm{alg}{G}$ of algebraic loops in $G$ and corresponding canonical elements. Th…

Sharp estimate on harmonic maps at conformal points in balls.

Fifty years ago, Eells and Sampson have proved a famous theorem in which they argued that any harmonic mapping $f:(M,g) \rightarrow (\bar{M},\bar{g})$ is totally geodesic if $(M, g)$ is a compact manifold with the nonnegative Ricci tensor and the section curvature of $(\bar{M},\bar{g})$ is nonpositive. Moreover, other …

Diffusion maps are a nonlinear manifold learning technique based on harmonic analysis of a diffusion process over the data. Out-of-sample extensions with computational complexity $\mathcal{O}(N)$, where $N$ is the number of points comprising the manifold, frustrate applications to online learning applications requiring…

We establish dimension-independent estimates related to heat operators e^{tL} on manifolds. We first develop a very general contractivity result for Markov kernels which can be applied to diffusion semigroups. Second, we develop estimates on the norm behavior of harmonic and non-negative subharmonic functions. We apply…

Motivated by the results of Wu-Yau-Zheng \cite{WuYauZheng}, we show that under a certain curvature assumption the harmonic representative of any boundary class of the Kähler cone is nonnegative.

The study derives formulas for functionals on surface with boundary under harmonic Ricci flow.

Study examines maximal domains of radial harmonic functions across different curvature types.

Study on vector fields on Lie groups reveals surprising algebraic coincidences.

We establish a regularity theorem for the Harmonic - Einstein Equation. As a byproduct of the local regularity, we also have a compactness theorem on Harmonic - Einstein equation. The method is mainly the Moser iteration technique which has been used and developed by \cite{BKN89}, \cite{Tian90}, \cite{TV05a} and others…

Brezis' open problem on harmonic maps resolved

The study shows that the visible range from a point on harmonic manifolds follows an exponential distribution.

Study dynamics of $L^p$-multipliers on harmonic manifolds with exponential volume growth.

We classify noncompact homogeneous spaces which are Einstein and asymptotically harmonic. This completes the classification of Riemannian harmonic spaces in the homogeneous case: Any simply connected homogeneous harmonic space is flat, or rank-one symmetric, or a nonsymmetric Damek-Ricci space. Independently, Y. Nikola…

Let (M,g) be a non-compact and complete Riemannian manifold with minimal horospheres and infinite injectivity radius. We prove that bounded functions on (M,g) satisfying the mean-value property are constant. We extend thus a result of A. Ranjan and H. Shah who proved a similar result for bounded harmonic functions on h…

Proves harmonicity equivalence on manifold metrics.

In this paper we introduce a significant improvement to the popular tree-based Stochastic Gradient Boosting algorithm using a wavelet decomposition of the trees. This approach is based on harmonic analysis and approximation theoretical elements, and as we show through extensive experimentation, our wavelet based method…

We say that a distribution is harmonic if it is harmonic when considered as a section of a Grassmann bundle. We find new examples of harmonic distributions and show nonexistense of harmonic distrubutions on some Riemannian manifolds by two different approaches. Firstly, we lift distributions to the second tangent bundl…

Method extends eigenfunction construction to non-symmetric spaces.

In this article we present an intrinsec construction of foliated Brownian motion via stochastic calculus adapted to foliation. The stochastic approach together with a proposed foliated vector calculus provide a natural method to work on harmonic measures. Other results include a decomposition of the Laplacian in terms …