Results 21 to 30 of about 104 (91)
Homotheties of cylindrically symmetric static manifolds and their global extension [PDF]
Cylindrically symmetric static manifolds are classified according to their homotheties and metrics. In each case the homothety vector fields and the corresponding metrics are obtained explicitly by solving the homothety equations. It turns out that these metrics admit homothety groups $H_m$, where $m=4,5,7,11$.
Qadir, Asghar, Sharif, M., Ziad, M.
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Extremal rate of convergence in continuous dynamics
Abstract This paper deals with semigroups of holomorphic self‐maps of the upper half‐plane that exhibit an extremal (i.e., the slowest possible) rate of convergence to their Denjoy–Wolff point. The main novelty lies in the parabolic case of zero hyperbolic step.
Francisco J. Cruz‐Zamorano +1 more
wiley +1 more source
New results on embeddings of self‐similar sets via renormalization
Abstract For self‐similar sets X,Y⊆R$X,Y\subseteq \mathbb {R}$, we obtain new results toward the affine embeddings conjecture of Feng–Huang–Rao (2014), and the equivalent weak intersections conjecture. We show that the conjecture holds when the defining maps of X,Y$X,Y$ have algebraic contraction ratios, and also for arbitrary Y$Y$ when the maps ...
Amir Algom, Michael Hochman, Meng Wu
wiley +1 more source
Cohomogeneity‐one solitons in Laplacian flow: Local, smoothly‐closing and steady solitons
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
Kuramoto Model on Sierpinski Gasket I: Harmonic Maps
ABSTRACT Motivated by the study of attractors in the Kuramoto model (KM) on graphs, approximating the Sierpinski gasket (SG), we revisit the problem of harmonic maps (HMs) from SG to the circle, first considered by Strichartz. We provide a geometric proof of Strichartz's theorem, which states that for a prescribed degree and suitable boundary ...
Georgi S. Medvedev, Matthew S. Mizuhara
wiley +1 more source
Homotheties and Coverings by Convex Sets
It is shown that, for any function $g$ that is weakly increasing on compact convex sets and has the property that if $λ\ge 0$ and $K^\prime$ is a translate of $λK$ then $g(K^\prime) =λg(K)$, then for any covering $\bigcup_i X_i\supseteq X$ of a compact convex set $X$ by finitely many compact convex sets $X_i$, the inequality $g(X) \leq \sum_i g(X_i ...
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Negativity‐preserving transforms of tuples of symmetric matrices
Abstract Compared to the entrywise transforms which preserve positive semidefiniteness, those leaving invariant the inertia of symmetric matrices reveal a surprising rigidity. We first obtain the classification of negativity preservers by combining recent advances in matrix analysis with some novel arguments relying on well‐chosen test matrices, Sidon ...
Alexander Belton +3 more
wiley +1 more source
ABSTRACT The article examines a boundary‐value problem in a bounded domain Ωε$$ {\Omega}_{\varepsilon } $$ consisting of perforated and imperforate regions, with Neumann conditions prescribed at the boundaries of the perforations. Assuming the porous medium has symmetric, periodic structure with a small period ε$$ \varepsilon $$, we analyze the limit ...
Taras Melnyk
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First and second sharp constants in Riemannian Gagliardo–Nirenberg inequalities
Abstract Let (M,g)$(M,g)$ be a smooth compact Riemannian manifold of dimension n≥2$n\ge 2$, 1+1 more source
Plank theorems and their applications: A survey
Abstract Plank problems concern the covering of convex bodies by planks in Euclidean space and are related to famous open problems in convex geometry. In this survey, we introduce plank problems and present surprising applications of plank theorems in various areas of mathematics.
William Verreault
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