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Related papers: On a natural map between twistor spaces

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We are studying the harmonic and twistor equation on Lorentzian surfaces, that is a two dimensional orientable manifold with a metric of signature $(1,1)$. We will investigate the properties of the solutions of these equations and try to…

Differential Geometry · Mathematics 2010-12-30 Frederik Witt

The identity map of an Einstein manifold is a critical point of both the classical energy functional and the conformal-bienergy functional. In this paper, we investigate the conformal-biharmonic stability of the identity map of compact…

Differential Geometry · Mathematics 2026-04-23 Volker Branding , Simona Nistor , Cezar Oniciuc

We show that the Atiyah-Patodi-Singer reduced $\eta$-invariant of the twisted Dirac operator on a closed $4m-1$ dimensional spin manifold, with the twisted bundle being the Witten bundle appearing in the theory of elliptic genus, is a…

Differential Geometry · Mathematics 2014-07-10 Fei Han , Weiping Zhang

For the twistor spaces of the Bochner-K\"ahler manifold $M = H^l \times P^n$, systems of holomorphic coordinates are constructed. As an application of them, an explicit description of the moduli space of relative deformations of fibers of…

dg-ga · Mathematics 2008-02-03 Yoshinari Inoue

We construct the twistor space associated with an HKT manifold, that is, a hyper-K\"ahler manifold with torsion, a type of geometry that arises as the target space geometry in two-dimensional sigma models with (4,0) supersymmetry. We show…

High Energy Physics - Theory · Physics 2009-10-09 P. S. Howe , G. Papadopoulos

Let $\Mg$ denote the moduli space of compact Riemann surfaces of genus $g$. Mumford had proved that, for each fixed genus $g$, there are isomorphisms asserting that certain higher $DET$ bundles over $\Mg$ are certain fixed…

alg-geom · Mathematics 2008-02-03 Indranil Biswas , Subhashis Nag , Dennis Sullivan

Let $(X,J)$ be a $4$-dimensional compact almost-complex manifold and let $g$ be a Hermitian metric on $(X,J)$. Denote by $\Delta_{\overline\partial}:=\overline\partial\overline\partial^*+\overline\partial^*\overline\partial$ the…

Differential Geometry · Mathematics 2026-05-27 Nicoletta Tardini , Adriano Tomassini

Quantization of general relativity in terms of SL(2,C)-connections (i.e. in terms of the complex Ashtekar variables) is technically difficult because of the non-compactness of SL(2,C). The difficulties concern the construction of a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Andrzej Okolow

Conformal harmonic maps from a 4-dimensional conformal manifold to a Riemannian manifold are maps satisfying a certain conformally invariant fourth order equation. We prove a general existence result for conformal harmonic maps, analogous…

Differential Geometry · Mathematics 2011-12-30 Olivier Biquard , Farid Madani

We study affine maps between affine manifolds. Even when the fibers are compact and diffeomorphic, two of them can inherit different affine structures from the source space. This leads to a fixed linear holonomy deformation theory of the…

Differential Geometry · Mathematics 2007-05-23 A. Tsemo

Two channels are said to be equivalent if they are degraded from each other. The space of equivalent channels with input alphabet $X$ and output alphabet $Y$ can be naturally endowed with the quotient of the Euclidean topology by the…

General Topology · Mathematics 2018-05-23 Rajai Nasser

This report attempts a clean presentation of the theory of harmonic maps from complex and K\"ahler manifolds to Riemannian manifolds. After reviewing the theory of harmonic maps between Riemannian manifolds initiated by Eells--Sampson and…

Differential Geometry · Mathematics 2020-10-08 Brice Loustau

The twistor space of a Riemannian 4-manifold carries two almost complex structures, $J_+$ and $J_-$, and a natural closed 2-form $\omega$. This article studies limits of manifolds for which $\omega$ tames either $J_+$ or $J_-$. This amounts…

Differential Geometry · Mathematics 2017-05-04 Joel Fine

We study the hypersymplectic geometry of the moduli space of solutions to Hitchin's harmonic map equations on a $G$-bundle. This is the split-signature analogue of Hitchin's Higgs bundle moduli space. Due to the lack of definiteness, this…

Differential Geometry · Mathematics 2014-02-17 Markus Röser

A harmonic map from a Riemannian manifold into a Grassmannian manifold is characterized by a vector bundle, a space of sections of this bundle and a Laplace operator. We apply our main theorem, itself a generalization of a Theorem of…

Differential Geometry · Mathematics 2014-08-08 Yasuyuki Nagatomo

We show that every diffeomorphism with mostly contracting center direction exhibits a geometric-combinatorial structure, which we call \emph{skeleton}, that determines the number, basins and supports of the physical measures. Furthermore,…

Dynamical Systems · Mathematics 2015-10-09 Dmitry Dolgopyat , Marcelo Viana , Jiagang Yang

We characterise when there exists a quasiisometric embedding between two solvable Baumslag-Solitar groups. This extends the work of Farb and Mosher on quasiisometries between the same groups. More generally, we characterise when there can…

Group Theory · Mathematics 2022-04-11 Patrick S. Nairne

The twistor space of representations on an open variety maps to a weight two space of local monodromy transformations around a divisor component at infinty. The space of $\sigma$-invariant sections of this slope-two bundle over the twistor…

Algebraic Geometry · Mathematics 2007-10-16 Carlos T. Simpson

We study the spectral location of strongly pattern equivariant Hamiltonians arising through configurations on a colored lattice. Roughly speaking, two configurations are "close to each other" if, up to a translation, they "almost coincide"…

Spectral Theory · Mathematics 2020-01-08 Siegfried Beckus , Jean Bellissard , Horia Cornean

We obtain conditions on the Lee form under which a holomorphic map between almost Hermitian manifolds is a harmonic map or morphism. Then we discuss under what conditions (i) the image of a holomorphic map from a cosymplectic manifold is…

dg-ga · Mathematics 2008-02-03 S. Gudmundsson , J. C. Wood