Results 31 to 40 of about 1,913,155 (139)

Construction of an A-manifold on a principal torus bundle

Annales Universitatis Paedagogicae Cracoviensis: Studia Mathematica, 2013
We construct a new example of an A-manifold, i.e. a Riemannian manifold with cyclic-parallel Ricci tensor. This condition can be viewed as a generalization of the Einstein condition.
Grzegorz Zborowski
doaj  

On Einstein-type manifold with cyclic parallel Ricci tensor

In this article, we derive an integral formula involving the tensor $D_{ijk}$ for compact Einstein-type manifolds with constant scalar curvature. As an application, we classify three-dimensional compact Einstein-type manifolds satisfying the cyclic parallel Ricci tensor condition, obtaining rigidity results that extend and unify previous work in the ...
Andrade, M., Baltazar, H., da Silva, A., Tavares, D.   +3 more
openaire   +2 more sources

Retinal Vessel Segmentation: A Comprehensive Review From Classical Methods to Deep Learning Advances (1982–2025)

Advanced Intelligent Systems, Volume 8, Issue 7, July 2026.
Four decades of retinal vessel segmentation research (1982–2025) are synthesized, spanning classical image processing, machine learning, and deep learning paradigms. A meta‐analysis of 428 studies establishes a unified taxonomy and highlights performance trends, generalization capabilities, and clinical relevance.
Avinash Bansal, Jan Kubíček, Jana Bahrová, Alice Varyšová, Martin Augustýnek, Marek Penhaker, Juraj Timkovič   +6 more
wiley   +1 more source

Cohomogeneity‐one solitons in Laplacian flow: Local, smoothly‐closing and steady solitons

Journal of the London Mathematical Society, Volume 113, Issue 6, June 2026.
Abstract We initiate a systematic study of cohomogeneity‐one solitons in Bryant's Laplacian flow of closed G2$\text{G}_2$‐structures on a 7‐manifold, motivated by the problem of understanding finite‐time singularities of that flow. Here, we focus on solitons with symmetry groups Sp(2)${\rm Sp}(2)$ and SU(3)${\rm SU}(3)$; in both cases, we prove the ...
Mark Haskins, Johannes Nordström
wiley   +1 more source

Experimental Dataset From Full‐Scale Near‐Collapse Tests on Two‐Storey, Two‐Bay Masonry‐Infilled Reinforced Concrete Frames With Timber‐Based Reinforced Concrete‐Timber Panel Seismic Retrofit

Earthquake Spectra, Volume 42, Issue 2, May 2026.
This study describes a dataset from an experimental campaign investigating the quasi‐static cyclic lateral response of two full‐scale, two‐storey, two‐bay reinforced concrete (RC) frames with masonry infills representative of mid‐20th century European construction practice.
Nikolaos Stathas, Andrea Bartolotti, Nicolò Damiani, Stathis Bousias, Francesco Smiroldo, Albino Angeli, Dmytro Dizhur, Francesco Graziotti, Ivan Giongo   +8 more
wiley   +1 more source

Deforming the Double‐Scaled SYK and Reaching the Stretched Horizon From Finite Cutoff Holography

Fortschritte der Physik, Volume 74, Issue 5, May 2026.
ABSTRACT We study the properties of the double‐scaled SYK (DSSYK) model under chord Hamiltonian deformations based on finite cutoff holography for general dilaton gravity theories with Dirichlet boundaries. The formalism immediately incorporates a lower‐dimensional analog of TT¯(+Λ2)$\text{T}\overline{\text{T}}(+\Lambda _2)$ deformations, denoted T2 ...
Sergio E. Aguilar‐Gutierrez
wiley   +1 more source

Lorentzian homogeneous structures with indecomposable holonomy

Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract For a Lorentzian homogeneous space, we study how algebraic conditions on the isotropy group affect the geometry and curvature of the homogeneous space. More specifically, we prove that a Lorentzian locally homogeneous space is locally isometric to a plane wave if it admits an Ambrose–Singer connection with indecomposable, non‐irreducible ...
Steven Greenwood, Thomas Leistner
wiley   +1 more source

Ricci Tensor Of Diagonal Metric [PDF]

, 1996
This paper was harvested from ArXiv.org and ArXiv identifier is arXiv:9602015v1Efficient formulae of Ricci tensor for an arbitrary diagonal metric are ...
Win, K. Z.
core   +3 more sources

Non-existence of Hopf real hypersurfaces in complex quadric with recurrent Ricci tensor [PDF]

, 2018
In this paper, we first introduce the notion of recurrent Ricci tensor which is the generalization of parallel Ricci tensor in the complex quadric Qm = SOm+2 /SOm SO2.
Shahid, Mohammad H., Bansal, Pooja
core   +1 more source

On‐Demand Cargo Release via Low‐Voltage Actuated Flexible Microchamber Arrays

Advanced Materials Technologies, Volume 11, Issue 8, 17 April 2026.
On‐demand triggering of cargoes’ release from free standing array of biocompatible microchambers may be actuated by electrical stimuli at voltages as low as 1 V, even making them suitable for implantation in living beings for drug delivery purposes.
Stefania Boi, Valentina Ricci, Maddalena Botti, Simone L. Marasso, Valentina Sinisi, Davide Vurro, Rishit Mohan Ahuja, Alberto Ballesio, Matteo Cocuzza, Saksham Sharma, Giuseppe Tarabella, Salvatore Iannotta, Pasquale D'Angelo   +12 more
wiley   +1 more source