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Related papers: Locally Sasakian Manifolds

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All known examples of simply-connected gradient K\"{a}hler-Ricci soliton in real dimension four are toric, and the symmetry is intrinsically related to the potential function $f$ and the scalar curvature $\SS$. In this article, we consider…

Differential Geometry · Mathematics 2026-01-23 Hung Tran

We extend profound results in pluripotential theory on Kahler manifolds to Sasaki setting via its transverse Kahler structure. As in Kahler case, these results form a very important piece to solve the existence of Sasaki metrics with…

Differential Geometry · Mathematics 2018-03-05 Weiyong He , Jun Li

In the paper, we study the generator problem of II$_1$ factors. By defining a new concept related to the number of generators of a von Neumann algebra, we are able to show that a large class of II$_1$ factors are singly generated, i.e.,…

Operator Algebras · Mathematics 2007-05-23 Junhao Shen

We introduce the manifold density function, which is an intrinsic method to validate manifold learning techniques. Our approach adapts and extends Ripley's $K$-function, and categorizes in an unsupervised setting the extent to which an…

Machine Learning · Computer Science 2024-02-16 Benjamin Holmgren , Eli Quist , Jordan Schupbach , Brittany Terese Fasy , Bastian Rieck

We investigate the probability that a random quadratic form in ${\mathbb{Z}}[x_1,...,x_n]$ has a totally isotropic subspace of a given dimension. We show that this global probability is a product of local probabilities. Our main result…

Number Theory · Mathematics 2022-12-21 Lycka Drakengren , Tom Fisher

In this work, we revisit quasi-Sasakian geometry in dimension three and examine how these structures interact with the foliation generated by the Reeb vector field and its basic cohomology. Through a deformation-based approach, we show that…

Differential Geometry · Mathematics 2025-12-29 Emmanuel Gnandi , Fortuné Massamba

In this note we give an explicit construction of Sasaki-Einstein metrics on a class of simply connected 7-manifolds with the rational cohomology of the 2-fold connected sum of $S^2\times S^5$. The homotopy types are distinguished by torsion…

Differential Geometry · Mathematics 2019-06-18 Charles P. Boyer , Christina Tønnesen-Friedman

We construct stationary solutions to the Einstein-Maxwell-current system by using the Sasakian manifold for the three-dimensional space. Both the magnetic field and the electric current in the solution are specified by the contact form of…

General Relativity and Quantum Cosmology · Physics 2020-12-07 Hideki Ishihara , Satsuki Matsuno

It is shown that a Banach space with locally uniformly convex dual admits an equivalent norm which is itself locally uniformly convex. It follows that on any such space all continuous real-valued functions may be uniformly approximated by…

Functional Analysis · Mathematics 2007-05-23 Richard Haydon

In this paper we study the 3-dimensional $(\varepsilon) $-para Sasakian manifolds. We obtain an necessary and sufficient condition for an $(\varepsilon ) $-para Sasakian 3 -manifold to be an indefinite space form. We show that a…

Differential Geometry · Mathematics 2016-08-14 Selcen Yüksel Perktaş , Erol Kılıç , Mukut Mani Tripathi , Sadık Keleş

BPS solutions of 5-dimensional supergravity correspond to certain gradient flows on the product M x N of a quaternionic-Kaehler manifold M of negative scalar curvature and a very special real manifold N of dimension n >=0. Such gradient…

High Energy Physics - Theory · Physics 2009-11-07 Dmitri V. Alekseevsky , Vicente Cortés , Chandrashekar Devchand , Antoine Van Proeyen

We show that any compact metric $f$-$K$-contact, respectively $S$-manifold is obtained from a compact $K$-contact, respectively Sasakian manifold by an iteration of constructions of mapping tori, rotations, and type II deformations.

Differential Geometry · Mathematics 2020-08-20 Oliver Goertsches , Eugenia Loiudice

We provide a general method to construct examples of quasi-Sasakian 3-structures on a (4n+3)-dimensional manifold. Moreover, among this class, we give the first explicit example of a compact 3-quasi-Sasakian manifold which is not the global…

Differential Geometry · Mathematics 2015-11-12 Beniamino Cappelletti-Montano , Antonio De Nicola , Ivan Yudin

We generate new 11-dimensional supergravity solutions from deformations based on U(1)^3 symmetries. The initial geometries are of the form AdS_4 x Y_7, where Y_7 is a 7-dimensional Sasaki-Einstein space. We consider a general family of…

High Energy Physics - Theory · Physics 2009-11-11 Changhyun Ahn , Justin F. Vazquez-Poritz

We study the non-relativity for two real analytic K\"ahler manifolds and complex space forms of three types. The first one is a K\"ahler manifold whose polarization of local K\"ahler potential is a Nash function in a local coordinate. The…

Complex Variables · Mathematics 2020-05-08 Xiaoliang Cheng , Yihong Hao

We look at the functional Y(M) = int_M K(x) dV(x) for compact Riemannian 2d-manifolds M, where K(x) = (2d)! (d!)^-1 (4pi)^-d int_T prod_k=1^d K_t_2k,t_2k+1(x) dt involves products of d sectional curvatures K_ij(x) averaged over the space T…

Differential Geometry · Mathematics 2020-06-02 Oliver Knill

In this paper we prove that any complete locally conformally flat quasi-Einstein manifold of dimension $n\geq 3$ is locally a warped product with $(n-1)$-dimensional fibers of constant curvature. This result includes also the case of…

Differential Geometry · Mathematics 2014-10-10 Giovanni Catino , Carlo Mantegazza , Lorenzo Mazzieri , Michele Rimoldi

We consider $\mathcal{N}=2$ supersymmetric pure gauge theories on toric K\"ahler manifolds, with particular emphasis on $\mathbb{CP}^2$. By choosing a vector generating a $U(1)$ action inside the torus of the manifold, we construct…

High Energy Physics - Theory · Physics 2014-12-16 Diego Rodriguez-Gomez , Johannes Schmude

Many compactly generated pseudo-groups of local transformations on 1-manifolds are realizable as the transverse dynamic of a foliation of codimension 1 on a compact manifold of dimension 3 or 4.

Geometric Topology · Mathematics 2015-03-04 Gaël Meigniez

The Mabuchi energy is an interesting geometric functional on the space of K\"ahler metrics that plays a crucial r\^ole in the study of the geometry of K\"ahler manifolds. We show that this functional, as well as other related geometric…

High Energy Physics - Theory · Physics 2012-03-13 Frank Ferrari , Semyon Klevtsov , Steve Zelditch