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From the kinematics of 137 spirals we find that the DM halo density profiles are self-similar at least out to R_opt and show core radii much larger that the corresponding disk scale-lenghts. The luminous regions of spirals consist of…

Astrophysics · Physics 2009-10-31 Paolo Salucci

It is shown that Denjoy-Carleman quasi analytic rings of germs of functions in two or more variables either complex or real valued that are stable under derivation and strictly larger than the ring of real-analytic germs are not Noetherian…

Algebraic Geometry · Mathematics 2014-10-16 Liat Kessler , Andreea C. Nicoara

In this short note it is shown that the category of neighborhood spaces is not cartesian closed.

Category Theory · Mathematics 2017-07-20 Giacomo Dossena

We present a detailed comparative study of the arcs and fragmented ring-like features in the haloes of the planetary nebulae (PNe) NGC 6543, NGC 7009, and NGC 7027 and the spiral pattern around the carbon star AFGL 3068 using high-quality…

Solar and Stellar Astrophysics · Physics 2020-05-27 M. A. Guerrero , G. Ramos-Larios , J. A. Toala , B. Balick , L. Sabin

Irregular (Irr) galaxies are gas-rich objects with recent or ongoing star formation. In absence of spiral density waves, star formation occurs largely stochastically. The scattered star-forming regions tend to be long-lived and migrate…

Astrophysics · Physics 2007-05-23 Eva K. Grebel

We find a class of twisted and differentially rotating neutron star magnetospheres that do not have a light cylinder, generate no wind and thus do not spin-down. The magnetosphere is composed of embedded differentially rotating flux…

High Energy Astrophysical Phenomena · Physics 2022-04-13 Maxim Lyutikov , Praveen Sharma

Recent VLBI (Very Long Baseline Interferometer) observations determined the distances and proper motions of star-forming regions in spiral arms directly. They showed that star-forming regions and young stars have large peculiar motions, as…

Astrophysics of Galaxies · Physics 2009-11-05 Junichi Baba , Yoshiharu Asaki , Junichiro Makino , Makoto Miyoshi , Takayuki R. Saitoh , Keiichi Wada

We present preliminary results of an off-line search for non-triggered gamma-ray bursts (GRBs) in the BATSE daily records for about 5.7 years of observations. We found more GRB-like events than the yield of the similar search of Kommers et…

Astrophysics · Physics 2009-10-31 B. Stern , Ya. Tikhomirova , M. Stepanov , D. Kompaneets , A. Berezhnoy , R. Svensson

In non-minimally coupled effective gravity theories one can have non-topological solitonic solutions. A typical solution is a spherical region with $G_{\it eff}=0$ outside and having the canonical Newtonian value inside. Such a spherical…

Astrophysics · Physics 2007-05-23 M. V. Safonova , D. Lohiya

Abr: We investigate whether the Hubble sequence can be reproduced by the relics of merger events. We verify that, at zmed=0.65, the abundant population of anomalous starbursts is mainly linked to the local spirals. Their morphologies are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 F. Hammer , H. Flores , M. Puech , Y. Yang , E. Athanassoula , M. Rodrigues , R. Delgado-Serrano

We consider non-linear plane gravitational waves as propagating space-time defects, and construct the Burgers vector of the waves. In the context of classical continuum systems, the Burgers vector is a measure of the deformation of the…

General Relativity and Quantum Cosmology · Physics 2021-01-27 F. L. Carneiro , S. C. Ulhoa , J. W. Maluf , J. F. da Rocha-Neto

The process of long-term stable mass transfer (or stripping) in a close neutron star binary system is possible at a sufficiently large initial asymmetry of the component masses. At the final stage of the evolution of such systems, the…

High Energy Astrophysical Phenomena · Physics 2025-12-01 Nikita Kramarev , Andrey Yudin

Motivated to study the geometry of the exotic spheres constructed in [5], we derive a necessary condition for non-negative sectional curvature in certain total spaces of Riemannian submersions with totally geodesic fibers. In particular, we…

Differential Geometry · Mathematics 2012-06-11 Llohann Sperança

Q-balls are non-topological solitons arising in scalar field theories. Solutions for rotating Q-balls (and the related boson stars) have been shown to exist when the angular momentum is equal to an integer multiple of the Q-ball charge $Q$.…

High Energy Physics - Theory · Physics 2024-04-11 Yahya Almumin , Julian Heeck , Arvind Rajaraman , Christopher B. Verhaaren

Theories possessing non-canonical kinetic terms are often studied for Q-ball states in an ad-hoc manner. This paper seeks to generalise their study for both thin- and thick-wall Q-balls. Specifically, we show that theories whose potential…

High Energy Physics - Phenomenology · Physics 2021-12-24 Olivier Lennon

We study two notions. One is that of spindle convexity. A set of circumradius not greater than one is spindle convex if, for any pair of its points, it contains every short circular arc of radius at least one, connecting them. The other…

Metric Geometry · Mathematics 2011-10-20 Karoly Bezdek , Zsolt Langi , Marton Naszodi , Peter Papez

We consider a single layer graphene nanoribbon with armchair edges in a longitudinally constant external potential and point out that its transport properties can be described by means of an effective non-Hermitian Hamiltonian. We show that…

Mesoscale and Nanoscale Physics · Physics 2011-06-28 Maurizio Fagotti , Claudio Bonati , Demetrio Logoteta , Paolo Marconcini , Massimo Macucci

We numerically study the origin of the multi-armed spiral structure observed in the circumnuclear gaseous mini-disks of nearby galaxies. We show that the presence of dust in such disks and its interaction with the gravitationally stable…

Astrophysics of Galaxies · Physics 2023-03-13 Roman Tkachenko , Vladimir Korchagin , Boris Jmailov

Structured-Gaussian beams are shown to be fully and uniquely represented by a collection of points (or constellation) on the surface of the modal Majorana sphere, providing a complete generalization of the modal Poincar\'e sphere to…

Optics · Physics 2020-10-16 R. Gutiérrez-Cuevas , S. A. Wadood , A. N. Vamivakas , M. A. Alonso

Noncommutative analogues of n-dimensional balls are defined by repeated application of the quantum double suspension to the classical low-dimensional spaces. In the `even-dimensional' case they correspond to the Twisted Canonical…

Operator Algebras · Mathematics 2014-02-26 Jeong Hee Hong , Wojciech Szymanski