Results 11 to 20 of about 130 (106)
Ruled real hypersurfaces of complex space forms
Kodai Mathematical Journal, 2010 Real hypersurfaces in non-flat complex space forms with integrable holomorphic distribution and symmetric φ-Ricci tensor which are φ-Einstein are ruled real hypersurfaces.
Hamada, Tatsuyoshi, Inoguchi, Jun-ichi
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On ruled real hypersurfaces in a complex space form
Tsukuba Journal of Mathematics, 1993 A real hypersurface \(M\) of a complex space form \(N\) is said to be ruled if \(M\) is foliated by one-codimensional totally geodesic complex submanifolds of \(N\). The authors provide a sufficient condition for a real hypersurface in a non-flat complex space form to be ruled.
Ahn, Seong-Soo +2 more
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Ruled real hypersurfaces having the same sectional curvature as that of an ambient nonflat complex space form [PDF]
Kodai Mathematical Journal, 2016 Ruled real hypersurfaces in a nonflat complex space form $\tilde{M}_n(c) (n ≧ 2)$ are obtained by having a one-codimensional foliation whose leaves are totally geodesic complex hypersurfaces of the ambient space. Motivated by a fact that the sectional curvature $K$ of every ruled real hypersurface $M$ in $\tilde{M}_n(c) (n ≧ 3)$ satisfies $|c/4| ≦ |K(X,
Maeda, Sadahiro +2 more
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Sectional curvatures of ruled real hypersurfaces in a complex hyperbolic space
Differential Geometry and its Applications, 2017 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Maeda, Sadahiro, Tanabe, Hiromasa
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Safe Stabilization Using Non‐Smooth Control Lyapunov Barrier Function
International Journal of Robust and Nonlinear Control, Volume 36, Issue 11, Page 5823-5835, 25 July 2026.ABSTRACT This paper addresses the challenge of safe stabilization, ensuring the system state reaches the origin while avoiding unsafe state regions. Existing approaches that rely on smooth Lyapunov barrier functions often fail to guarantee a feasible controller. To overcome this limitation, we introduce the non‐smooth control Lyapunov barrier function (
Jianglin Lan +3 more
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Affine hypersurfaces and superintegrable systems
Journal of the London Mathematical Society, Volume 114, Issue 1, July 2026.Abstract It was recently shown that under mild assumptions, second‐order conformally superintegrable systems can be encoded in a (0,3)‐tensor, called structure tensor. For abundant systems, this approach led to algebraic integrability conditions that essentially allow one to restore a system from the knowledge of its structure tensor in a point on the ...
Vicente Cortés, Andreas Vollmer
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Fortschritte der Physik, Volume 74, Issue 6, June 2026.ABSTRACT We present a clear, step‐by‐step method for counting degrees of freedom and identifying constraints in general field theories. This approach, grounded in the works of Einstein, Hilbert, Cartan, Kuranishi, and, more recently, Seiler, is neither Lagrangian nor Hamiltonian in nature. Instead, it applies directly to the field equations. We offer a
Lavinia Heisenberg
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Vertical Deformation Mapping: Steering Optimiser Toward Flat Minima
CAAI Transactions on Intelligence Technology, Volume 11, Issue 3, Page 835-846, June 2026.ABSTRACT Standard deep learning optimisation is typically conducted on shape‐fixed loss surfaces. However, shape‐fixed loss surfaces may impede optimisers from reaching flat regions closely associated with strong generalisation. In this work, we propose a new paradigm named deformation mapping to deform the loss surface during optimisation.
Liangming Chen +4 more
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Congruence classes of minimal ruled real hypersurfaces in a nonflat complex space form
Hokkaido Mathematical Journal, 2014 In this paper we study congruency of minimal ruled real hypersurfaces in a nonflat complex space form with respect to the action of its isometry group. We show that those in a complex hyperbolic space are classified into 3 classes and show that those in a complex projective space are congruent to each other hence form just one class.
ADACHI, Toshiaki +2 more
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The singularity category and duality for complete intersection groups
Bulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.Abstract If G$G$ is a finite group, the structure of the modular representation theory depends on the cochains C∗(BG;k)$C^*(BG; k)$, viewed as a commutative ring spectrum. We consider here its singularity category (in the sense of the author and Stevenson [Adv. Math.
J. P. C. Greenlees
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