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.
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…
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…
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…
We study the classification of special almost hermitian manifolds in Gray and Hervella's type classes. We prove that the exterior derivatives of the symplectic form and the complex volume form contain all the information about the intrinsic torsion of the $\SUn(n)$-structure. Furthermore, we apply the obtained results …
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 $…
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…
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.
We construct new explicit toric scalar-flat K{ä}hler ALE metrics on weighted projective spaces of non-compact type, which we use to obtain smooth extremal K{ä}hler metrics on appropriate resolutions of orbifolds. In particular, we obtain new extremal metrics certain resolutions of weighted projective spaces of compact …
We show how certain topological properties of co-K{ä}hler manifolds derive from those of the Kähler manifolds which construct them. We go beyond Betti number results and describe the cohomology algebra structure of co-Kähler manifolds. As a consequence, we prove that co-Kähler manifolds satisfy the Toral Rank Conjectur…
We study the fundamental groups of compact Sasakian manifolds, which we call Sasaki groups. It is shown that all known Ka¨hler groups are Sasaki, in particular, all finite groups are Sasaki. On the other hand, we show there exists many restrictions on the fundamental groups of compact Sasakian manifolds. We als…
Almost contact structures can be identified with sections of a twistor bundle and this allows to define their harmonicity, as sections or maps. We consider the class of nearly cosymplectic almost contact structures on a Riemannian manifold and prove curvature identities which imply the harmonicity of their parametrizin…
Let (M3,g0) be a complete noncompact Riemannian 3-manifold with nonnegative Ricci curvature and with injectivity radius bounded away from zero. Suppose that the scalar curvature R(x)→0 as x→∞. Then the Ricci flow with initial data (M3,g0) has a long time solution. This extends a recent result of …
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…
Let Mn be a complete noncompact Ka¨hler manifold of complex dimension n with nonnegative holomorphic bisectional curvature. Denote by O_d(M^n)thespaceofholomorphicfunctionsofpolynomialgrowthofdegreeatmostdonM^n.Inthispaperweprovethatdim_{\mathbb{C}}{\mathcal{O}}_d(…