English
Related papers

Related papers: Star fows and multisingular hyperbolicity

200 papers

Most star complexes are in fact complexes of stars, clusters and gas clouds; term "star complexes" was introduced as general one disregarding the preferential content of a complex. Generally the high rate of star formation in a complex is…

Astrophysics · Physics 2010-11-23 Yuri N. Efremov

Fast-slow systems with three slow variables and gradient structure in the fast variables have, generically, hyperbolic umbilic, elliptic umbilic or swallowtail singularities. In this article we provide a detailed local analysis of a…

Dynamical Systems · Mathematics 2024-08-20 Hildeberto Jardón-Kojakhmetov , Christian Kuehn , Maximilian Steinert

We consider the Cauchy problem for first order systems. Assuming that the set of the singular points of the characteristic variety is a smooth manifold and the characteristic values are real and semi-simple we introduce a new class which is…

Analysis of PDEs · Mathematics 2020-12-23 Tatsuo Nishitani

We show uniqueness of cylindrical blowups for mean curvature flow in all dimension and all codimension. Cylindrical singularities are known to be the most important; they are the most prevalent in any codimension. Mean curvature flow in…

Differential Geometry · Mathematics 2020-02-17 Tobias Holck Colding , William P. Minicozzi

Singular and sectional hyperbolic sets are the objects of the extension of the classical Smale Hyperbolic Theory to flows having invariant sets with singularities accumulated by regular orbits within the set. It is by now well-known that…

Dynamical Systems · Mathematics 2021-07-27 Vitor Araujo , Vinicius Coelho , Luciana Salgado

We prove that a Hamiltonian star system, defined on a 2d-dimensional symplectic manifold M, is Anosov. As a consequence we obtain the proof of the stability conjecture for Hamiltonians. This generalizes the 4-dimensional results in [6].

Dynamical Systems · Mathematics 2013-04-16 M. Bessa , M. J. Torres , J. Rocha

We prove that every factor map between topological flows preserves the standard shadowing property if it is injective except for a closed orbit that shrinks to a singularity. As an application, we construct a $C^\infty$-flow on a…

Dynamical Systems · Mathematics 2025-04-02 Sogo Murakami

We prove the existence of infinitely many periodic orbits of symplectomorphisms isotopic to the identity if they admit at least one hyperbolic periodic orbit and satisfy some condition on the flux. Our result is proved for a certain class…

Symplectic Geometry · Mathematics 2015-08-27 Marta Batoréo

Most star complexes are in fact complexes of stars, clusters and gas clouds; term "star complexes" was introduced as general one disregarding the preferential content of a complex. Generally the high rate of star formation in a complex is…

Astrophysics · Physics 2007-05-23 Yu. N. Efremov

We consider the evolution by inverse mean curvature flow of a closed, mean convex and star-shaped hypersurface in the complex hyperbolic space. We prove that the flow is defined for any positive time, the evolving hypersurface stays…

Differential Geometry · Mathematics 2018-03-29 Giuseppe Pipoli

A sectional-Anosov flow on a manifold M is a C^1 vector field inwardly transverse to the boundary for which the maximal invariant is sectional-hyperbolic. We prove that every attractor of every vector field C^1 close to a transitive…

Dynamical Systems · Mathematics 2013-09-02 A. M. López

Singular hyperbolicity is a weakened form of hyperbolicity that has been introduced for vector fields in order to allow non-isolated singularities inside the non-wandering set. A typical example of a singular hyperbolic set is the Lorenz…

Dynamical Systems · Mathematics 2020-01-22 Sylvain Crovisier , Dawei Yang

The formation of massive stars is a highly complex process in which it is not clear whether the star-forming gas is in global gravitational collapse or in an equilibrium state, supported by turbulence. By studying one of the most massive…

Astrophysics of Galaxies · Physics 2015-05-18 N. Schneider , T. Csengeri , S. Bontemps , F. Motte , R. Simon , P. Hennebelle , C. Federrath , R. Klessen

The current observational evidences suggest there are about hundred billion galaxies in the observable universe and within each, on an average, about hundred billion stars. But no cosmological model indicates as to why there are these many…

General Physics · Physics 2012-02-08 C Sivaram , Kenath Arun

Most stars are formed in a cluster or association, where the number density of stars can be high. This means that a large fraction of initially-single stars will undergo close encounters with other stars and/or exchange into binaries. We…

We have shown analytically that shapes of incompressible stars could be prolate if appropriate meridional flows exist. Although this result is strictly valid only if either the meridional flow or the rotation is absent and the vorticity is…

Solar and Stellar Astrophysics · Physics 2013-12-11 Kotaro Fujisawa , Yoshiharu Eriguchi

We introduce a new version of expansiveness for flows. Let $M$ be a compact Riemannian manifold without boundary and $X$ be a $C^1$ vector field on $M$ that generates a flow $\varphi_t$ on $M$. We call $X$ {\it rescaling expansive} on a…

Dynamical Systems · Mathematics 2017-06-30 Xiao Wen , Lan Wen

Observations have suggested that galactic outflows contain substantial amounts of dense and clumpy molecular gas, creating favourable conditions for igniting star formation. Indeed, theoretical models and hydrodynamical simulations have…

There exists a $C^2$-open and $C^1$-dense subset of vector fields exhibiting singular-hyperbolic attracting sets (with codimension-two stable bundle), in any $d$-dimensional compact manifold ($d\ge3$), which mix exponentiallu with respect…

Dynamical Systems · Mathematics 2022-09-27 Vitor Araujo

The engulfment of substellar bodies (SBs, such as brown dwarfs and planets) by giant stars is a possible explanation for rapidly rotating giants, lithium-rich giants, and the presence of SBs in close orbits around subdwarfs and white…