A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.
Pluriharmonic maps form an important class of harmonic maps which includes holomorphic maps. We study their morphisms, in particular the inter-relationships between (1,1)-geodesic, pluriharmonic and ±holomorphic maps. Then we characterise pluriharmonic morphisms between Hermitian manifolds. We make a special stud…
We introduce the complete lifts of maps between (real and complex) Euclidean spaces and study their properties concerning holomorphicity, harmonicity and horizontal weakly conformality. As applications, we are able to use this concept to characterize holomorphic maps $φ:{\Bbb C}^{m}\supset U\longrightarrow {\Bbb C}^{n}…
For the sake of hyperk{ä}hler SYZ conjecture, finding holomorphic Lagrangian fibrations becomes an important issue. Toric hyperk{ä}hler manifolds are real dimension 4n non-compact hyperk{ä}hler manifolds which are quaternion analog of toric varieties. The n dimensional residue circle action on it admitting a hyperk…
Toric hyperk{ä}hler manifolds are quaternion analog of toric varieties. Bielawski pointed out that they can be glued by cotangent bundles of toric varieties. Following his idea, viewing both toric varieties and toric hyperk{ä}her manifolds as GIT quotients, we first establish geometrical criteria for the semi-stable po…
In this note we prove the following result: There is a positive constant ε(n,Λ) such that if Mn is a simply connected compact Ka¨hler manifold with sectional curvature bounded from above by Λ, diameter bounded from above by 1, and with holomorphic bisectional curvature H≥−ε(n,Λ), then Mn is dif…
In this paper we prove that for a complete, connected and oriented Käler affine manifold (M,G) of dimension n, if it is Kähler affine Ricci flat or the Ka¨hler affine scalar curvature S≡0, (n≤5), then the universal covering manifold M of M is isometric to the Euclidean n-space $…
We investigate invariants of compact hyperk{ä}hler manifolds introduced by Rozansky and Witten: they associate an invariant to each graph homology class. It is obtained by using the graph to perform contractions on a power of the curvature tensor and then integrating the resulting scalar-valued function over the manifo…
For any complete noncompact Ka¨hler manifold with nonnegative and bounded holomorphic bisectional curvature,we provide the necessary and sufficient condition for non-ancient solution to the Ricci flow in this paper.
The aim of this thesis is to construct new examples of compact orbifolds O4(Θ) which admit a self dual Einstein (SDE) metric of positive scalar curvature s>0, with a one-dimensional group of isometries. In particular we want to prove that these examples are different from those described by Boyer, Galick…
We study the behavior of the modular class of a Lie algebroid under general Lie algebroid morphisms by introducing the relative modular class. We investigate the modular classes of pull-back morphisms and of base-preserving morphisms associated to Lie algebroid extensions. We also define generalized morphisms, includin…
Let $\g\_2$ be the Hochschild complex of cochains on $C^\infty(\RM^n)$ and $\g\_1$ be the space of multivector fields on $\RM^n$. In this paper we prove that given any G_∞-structure ({\rm i.e.} Gerstenhaber algebra up to homotopy structure) on $\g\_2$, and any C_∞-morphism φ ({\rm i.e.} morphism of co…
P. Baird and the second author studied harmonic morphisms from a three-dimensional simply-connected space form to a surface and obtained a complete local and global classification of them. In this paper, we obtain a description of all harmonic morphisms from any three-dimensional Euclidean and spherical space form to a…
We define what we call morphisms of Cartan connections. We generalize the main theorems on Cartan connections to theorems on morphisms. Many of the known constructions involving Cartan connections turn out to be examples of morphisms. We prove some basic results concerning completeness of Cartan connections. We provide…