Results 71 to 80 of about 373,220 (224)
Anisotropically Weighted and Nonholonomically Constrained Evolutions on Manifolds
Entropy, 2016 We present evolution equations for a family of paths that results from anisotropically weighting curve energies in non-linear statistics of manifold valued data. This situation arises when performing inference on data that have non-trivial covariance and
Stefan Sommer
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Density‐Valued ARMA Models by Spline Mixtures
Journal of Time Series Analysis, EarlyView.ABSTRACT This paper proposes a novel framework for modeling time series of probability density functions by extending autoregressive moving average (ARMA) models to density‐valued data. The method is based on a transformation approach, wherein each density function on a compact domain [0,1]d$$ {\left[0,1\right]}^d $$ is approximated by a B‐spline ...
Yasumasa Matsuda, Rei Iwafuchi
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On the sectional curvature of lightlike submanifolds
Journal of Inequalities and Applications, 2016 The main purpose of this paper is to show how to obtain rigidity theorems with the help of curvature invariants in submanifolds of a semi-Riemannian manifold.
Erol Kılıç, Mehmet Gülbahar
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Some properties of biconcircular gradient vector fields; pp. 162–169 [PDF]
Proceedings of the Estonian Academy of Sciences, 2009 We consider a Riemannian manifold carrying a biconcircular gradient vector field X, having as generative a closed torse forming U. The existence of such an X is determined by an exterior differential system in involution depending on two arbitrary ...
Adela Mihai
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Maximal symplectic torus actions
Bulletin of the London Mathematical Society, EarlyView.Abstract There are several different notions of maximal torus actions on smooth manifolds, in various contexts: symplectic, Riemannian, complex. In the symplectic context, for the so‐called isotropy‐maximal actions, as well as for the weaker notion of almost isotropy‐maximal actions, we give classifications up to equivariant symplectomorphism.
Rei Henigman
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Journal of Inequalities and Applications, 2018 Given a null hypersurface of a Lorentzian manifold, we isometrically immerse a null hypersurface equipped with the Riemannian metric (induced on it by the rigging) into a Riemannian manifold suitably constructed on the Lorentzian manifold.
Karimumuryango Ménédore
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Comonotonic‐Based Time Series Clustering With Constraints: A Review and a Conceptual Framework
Environmetrics, Volume 36, Issue 8, December 2025.ABSTRACT Time series clustering is a widely used unsupervised learning approach that identifies groups of similar time series to uncover hidden patterns in complex datasets. In recent years, this technique has gained traction in the analysis of geo‐referenced time series, where spatial information must be incorporated into the dissimilarity measure to ...
Alessia Benevento +2 more
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(Random) Trees of Intermediate Volume Growth
Random Structures &Algorithms, Volume 67, Issue 4, December 2025.ABSTRACT For every function g:ℝ≥0→ℝ≥0$$ g:{\mathbb{R}}_{\ge 0}\to {\mathbb{R}}_{\ge 0} $$ that grows at least linearly and at most exponentially, if it is sufficiently well‐behaved, we can construct a tree T$$ T $$ of uniform volume growth g$$ g $$, or more precisely, C1·g(r/4)≤|BG(v,r)|≤C2·g(4r),for allr≥0andv∈V(T),$$ {C}_1\cdotp g\left(r/4\right)\le \
George Kontogeorgiou, Martin Winter
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On the singularities of a Riemannian manifold
Publicationes mathematicae (Debrecen), 2022 G. Szekeres
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Fat equator effect and minimality in immersions and submersions of the sphere
Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.Abstract Inspired by the equatorial concentration of measure phenomenon in the sphere, a result which is deduced from the general (and intrinsic), concentration of measure in Sn(1)$\mathbb {S}^n(1)$, we describe in this paper an equatorial concentration of measure satisfied by the closed (compact without boundary), isometric and minimal immersions x:Σm→
Vicent Gimeno i Garcia, Vicente Palmer
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