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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.

168,657 papers · 148 categories

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53107160213 · Jun 202019922001200920172026
48 results for Berger-type deformed Sasaki metric

Study geodesics on a modified cotangent bundle over Kählerian manifolds.

problem Investigate geodesics on a modified cotangent bundle.
method Introduced Berger-type deformed Sasaki metric, investigated Levi-Civita connections, and studied geodesics.
result Geodesic properties on modified cotangent bundles.

Study harmonicity on tangent bundles with a specific metric.

problem Harmonicity of canonical projection and vector field in tangent bundles.
method Investigate harmonicity on tangent bundles with a Berger-type deformed Sasaki metric.
result Characterized conditions for harmonicity of the canonical projection and vector field.

Study on new metrics on para-Kähler-Norden manifolds with conformal deformation.

problem Exploring geometric and harmonic properties of new metrics.
method Conformal deformation of Berger-type metric, analysis of Levi-Civita link, study of curvature varieties, and harmonic maps.
result Detailed examination of curvature varieties and harmonic maps on the manifold.

We consider the stability of Sasaki-extremal metrics under deformations of the complex structure on the Reeb foliation. Given such a deformation preserving the action of a compact subgroup of the automorphism group of a Sasaki-extremal structure, a sufficient condition is given involving the nondegeneracy of the relati…

2012-04-07abs ↗pdf ↗

We classify simply connected compact Sasaki manifolds of dimension 2n+12n+1 with positive transverse bisectional curvature. In particular, the Kähler cone corresponding to such manifolds must be bi-holomorphic to $\C^{n+1}\backslash \{0\}$. As an application we recover the Mori-Siu-Yau theorem on the Frankel conjecture a…

2012-02-13abs ↗pdf ↗

Study on deformations of Einstein and nearly G2 structures in 3-Sasaki manifolds.

problem Deformation theory of Einstein and nearly G2 structures in 3-Sasaki manifolds.
method Systematic study of deformation theory, focusing on infinitesimal deformations and their parametrization via eigenfunctions of the basic Laplacian.
result Infinitesimal Einstein deformations of g1/5g_{1/\sqrt{5}} coincide with infinitesimal G2G_2 deformations of φ1/5\varphi_{1/\sqrt{5}}.

We define K-stability of a polarized Sasakian manifold relative to a maximal torus of automorphisms. The existence of a Sasaki-extremal metric in the polarization is shown to imply that the polarization is K-semistable. Computing this invariant for the deformation to the normal cone gives an extention of the Lichnerowi…

2016-08-22abs ↗pdf ↗

In [11] it was proved that, given a compact toric Sasaki manifold of positive basic first Chern class and trivial first Chern class of the contact bundle, one can find a deformed Sasaki structure on which a Sasaki-Einstein metric exists. In the present paper we first prove the uniqueness of such Einstein metrics on com…

2007-01-04abs ↗pdf ↗

We prove the existence of Sasaki-Einstein metrics on certain simply connected 5-manifolds where until now existence was unknown. All of these manifolds have non-trivial torsion classes. On several of these we show that there are a countable infinity of deformation classes of Sasaki-Einstein structures.

2009-03-01abs ↗pdf ↗

We consider an extension of the results of S. Bando, R. Kobyashi, G. Tian, and S. T. Yau on the existence of Ricci-flat Kähler metrics on quasi-projective varieties Y=X\D with α[D]=c_1(X), α>1. The requirement that D admit a Kähler-Einstein metric is generalized to the condition that the link S in the normal bundle of …

2008-03-02abs ↗pdf ↗

We give a correspondence between toric 3-Sasaki 7-manifolds S and certain toric Sasaki-Einstein 5-manifolds M. These 5-manifolds are all diffeomorphic to k#(S^2\times S^3), where k=2b_2(S)+1, and are given by a pencil of Sasaki embeddings of M in S and are given concretely by the zero set of a component of the 3-Sasaki…

2006-07-27abs ↗pdf ↗

New cohomology ηη for deformed Sasaki-Einstein manifolds derived from Dolbeault cohomology.

problem Developing a new cohomology structure for deformed Sasaki-Einstein manifolds.
method Introducing ηη-cohomology defined by a CR structure and a holomorphic function ff with non-vanishing ηdfη\equiv \mathrm{d}f.
result Established a direct relation between the cyclic homologies of the Calabi-Yau algebra and the ηη-cohomology groups.

Several Einstein-Sasaki 7-metrics appearing in the physical literature are fibered over four dimensional Kahler-Einstein metrics. Instead we consider here the natural Kahler-Einstein metrics defined over the twistor space Z of any quaternion Kahler 4-space, together with the corresponding Einstein-Sasaki metrics. We wo…

2007-01-12abs ↗pdf ↗

New spinorial field equation reveals geometric properties of Sasaki manifolds.

problem Exploring new spinorial field equations on Sasaki manifolds.
method Developed H\mathcal{H}-Killing spinors for 33-(α,δ)(α,δ)-Sasaki manifolds.
result Obtained one-to-one correspondence between H\mathcal{H}-Killing spinors on dual pairs of Sasaki spaces.

In the first part, we define and investigate new classes of almost 3-contact metric manifolds, with two guiding ideas in mind: first, what geometric objects are best suited for capturing the key properties of almost 3-contact metric manifolds, and second, the newly defined classes should admit 'good' metric connections…

2018-04-18abs ↗pdf ↗

We extend to the Sasakian setting a result of Tian and Zhu about the decomposition of the Lie algebra of holomorphic vector fields on a Kähler manifold in the presence of a Kähler-Ricci soliton. Furthermore we apply known deformations of Sasakian structures to a Sasaki-Ricci soliton to obtain a stability result concern…

2013-07-12abs ↗pdf ↗

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…

2009-09-27abs ↗pdf ↗

The paper explores existence and non-existence of constant scalar curvature and extremal Sasaki metrics.

problem Existence and non-existence of constant scalar curvature and extremal Sasaki metrics.
method Analyzing natural Sasaki-Boothby-Wang manifolds and extremal Sasaki metrics on admissible projective bundles.
result The extremal Sasaki--Reeb cone is not necessarily connected and can be empty even in the non-Gorenstein case.

Exposes new connections between weighted Kähler-Ricci solitons and Ricci-flat Kähler cone metrics.

problem Exploring connections between weighted Kähler-Ricci solitons and Ricci-flat Kähler cone metrics.
method Surveying and reviewing recent works, transforming complex Monge-Ampère equations, and proving the YTD conjecture.
result Established a transformation from irregular Sasaki-Einstein metrics to gg-solitons on quasi-regular quotients.

The paper studies para-Sasaki-like manifolds with a new metric connection.

problem Investigating new geometric structures on para-Sasaki-like manifolds.
method Deriving relations between connections, analyzing curvature tensors, studying solitons, constructing examples.
result Derived relations and properties of para-Sasaki-like manifolds with the generalized symmetric metric connection.

The paper constructs Einstein Sasaki metrics on solvable Lie groups.

problem Constructing left-invariant Einstein pseudo-Riemannian Sasaki metrics on solvable Lie groups.
method Characterizing pseudo-Kähler structures and derivations giving rise to Sasaki-Einstein metrics.
result Classification of z\mathfrak z-standard Sasaki solvable Lie algebras of dimension 7\leq 7.

We give a survey of our recent work describing a method which combines the Sasaki join construction with the admissible Kähler construction of to obtain new extremal and new constant scalar curvature Sasaki metrics, including Sasaki-Einstein metrics. The constant scalar curvature Sasaki metrics also provide explicit so…

2015-06-03abs ↗pdf ↗

We describe a general procedure for constructing new Sasaki metrics of constant scalar curvature from old ones. Explicitly, we begin with a regular Sasaki metric of constant scalar curvature on a 2n+1-dimensional compact manifold M and construct a sequence, depending on four integer parameters, of rays of constant scal…

2014-02-11abs ↗pdf ↗

The paper proves the existence of Sasaki-Einstein metrics on specific Sasakian manifolds.

problem Proving the existence of conic Sasaki-Einstein metrics on log Fano Sasakian manifolds of dimension five.
method Deriving uniform L^{4}-bounds and analyzing the conic Sasaki-Ricci flow.
result Existence of conic Sasaki-Einstein metrics on log Fano Sasakian manifolds of dimension five.

By combining the join construction from Sasakian geometry with the Hamiltonian 2-form construction from Kähler geometry, we recover Sasaki-Einstein metrics discovered by physicists. Our geometrical approach allows us to give an algorithm for computing the topology of these Sasaki-Einstein manifolds. In particular, we e…

2013-09-26abs ↗pdf ↗

Formula derived for Laplace-Beltrami spectrum on homogeneous spaces.

problem Calculating the spectrum of the Laplace-Beltrami operator on homogeneous spaces.
method Formula derivation based on eigenvalues of a generalized Casimir operator and spherical representations.
result First detailed computation and investigation of the spectrum for a family of metrics on the Aloff-Wallach manifold.

We establish an equivalence between conformally Einstein--Maxwell Kahler 4-manifolds (recently studied in many works) and extremal Kahler 4-manifolds (in the sense of Calabi) with nowhere vanishing scalar curvature. The corresponding pairs of Kahler metrics arise as transversal Kahler structures of Sasaki metrics compa…

2018-10-24abs ↗pdf ↗

Study identifies Kähler-Einstein, Kähler-Ricci soliton, and Sasaki-Einstein metrics on log del Pezzo surfaces.

problem Characterizing log del Pezzo surfaces with specific geometric properties.
method Examining two classes of non-toric log del Pezzo surfaces and analyzing their geometric properties.
result Examples found that admit Kähler-Ricci solitons but not Sasaki-Einstein cone links.

New Sasaki metrics with constant scalar curvature on sphere bundles are constructed.

problem Constructing extremal Sasaki metrics with constant scalar curvature.
method Using the fiber join construction and a recent existence theorem for constant scalar curvature Sasaki metrics.
result Explicit constructions of constant scalar curvature Sasaki metrics on specific sphere bundles.

Motivated by the study of coupled Kähler-Einstein metrics by Hultgren and Witt Nyström and coupled Kähler-Ricci solitons by Hultgren, we study in this paper coupled Sasaki-Einstein metrics and coupled Sasaki-Ricci solitons. We first show an isomorphism between the Lie algebra of all transverse holomorphic vector fields…

2018-12-10abs ↗pdf ↗

Unified method to compute Laplace spectra on homogeneous principal bundles.

problem Computing the Laplace-Beltrami spectrum on homogeneous principal bundles.
method Unified representation-theoretic approach using generalized canonical variations and spectral branching criterion.
result Explicit formulas for the full spectra of several geometric families.