相关论文: Flocks of Cones: Star Flocks
We answer the question whether, when forming constellations in the night sky, people in astronomical cultures around the world and through time consistently imagined and assigned the same symbolism to the same (type of) star group. Evidence…
A quark-cluster state, rather than the color-super-conductivity state, may appear in matter with low-temperature but high density, since the phase transition of chiral symmetry broken and that of color-confinement could not occur…
Given a collection of points in the plane, classifying which subsets are collinear is a natural problem and is related to classical geometric constructions. We consider collections of points in a projective plane over a finite field such…
Over the last decade, HST imaging studies have revealed that the centers of most galaxies are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and spectra, these sources…
Globular clusters are ancient stellar populations with no star formation or core-collapse supernovae. Several lines of evidence suggest that globular clusters are rich in planets. If so, and if advanced civilizations can develop there, then…
We construct the quadratic analogue of the boson Fock functor. While in the first order case all contractions on the 1--particle space can be second quantized, the semigroup of contractions that admit a quadratic second quantization is much…
Collective motion - or flocking - is an emergent phenomena that underlies many biological processes of relevance, from cellular migrations to animal groups movement. In this work, we derive scaling relations for the fluctuations of the mean…
P-stars are compact stars made of up and down quarks in $\beta$-equilibrium with electrons in a chromomagnetic condensate. P-stars are able to account for compact stars as well as stars with radius comparable with canonical neutron stars.…
In network coding, a flag code is a set of sequences of nested subspaces of $\mathbb{F}_q^n$, being $\mathbb{F}_q$ the finite field with $q$ elements. Flag codes defined as orbits of a cyclic subgroup of the general linear group acting on…
Star clusters stand at the intersection of much of modern astrophysics: the interstellar medium, gravitational dynamics, stellar evolution, and cosmology. Here we review observations and theoretical models for the formation, evolution, and…
In this paper, I review to what extent we can understand the photometric properties of star clusters, and of low-mass, unresolved galaxies, in terms of population synthesis models designed to describe `simple stellar populations' (SSPs),…
(Abridged) Poorly-populated star clusters may have photometric and structural properties not much different from asterisms, to the point that, in some cases, widely-used databases present conflicting classifications. We investigate the…
Large numbers of young stars are formed in merging galaxies, such as the Antennae galaxies. Most of these stars are formed in compact star clusters (i.e., super star clusters), which have been the focus of a large number of studies.…
We consider flocks of artificial birds and study the emergence of V-like formations during flight. We introduce a small set of fully distributed positioning rules to guide the birds' movements and demonstrate, by means of simulations, that…
We compute and present the distribution in mass of single and binary neutron stars, strange stars, and black holes. The calculations were performed using a stellar population synthesis code. We follow evolution of massive single stars as…
This article explains an optimization-based approach for counting and localizing stars within a small cluster, based on photon counts in a focal plane array. The array need not be arranged in any particular way, and relatively small numbers…
Ordinary polytopes are known as a non-simplicial generalization of the cyclic polytopes. The face vectors of ordinary polytopes are shown to be log-concave.
We describe all families of star-shaped n-polygons in the Euclidean plane with prescribed perimeter and area ; they are leaves of a foliation F on the space of star-shaped n-polygons. By the way, we study some geometric properties of convex…
Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing…
New models are presented for star-forming condensations in clusters. In each model, the condensation mass increases linearly with radius on small scales, and more rapidly on large scales, as in "thermal-nonthermal" models. Spherical…