4,296 research outputs found
Rendez-vous of dwarfs
We present observations of multiple system of dwarf galaxies at the Russian
6-m telescope and the GMRT (Giant Metrewave Radio Telescope). The optical
observations are a part of the programme Study of Groups of Dwarf Galaxies in
the Local Supercluster. The group of galaxies under consideration looks like
filament of 5 dwarfs. Two faint galaxies show peculiar structure. Long slit
spectrum reveals inner motions about 150 km/s in one of them. It suggests that
the galaxy is on stage of ongoing interaction. Probably, we see the group in
moment of its formation.Comment: 2 pages, 3 figures; to appear in the proceedings of the conference "A
Universe of dwarf galaxies" (Lyon, June 14-18, 2010
On Thermodynamics of Rational Maps. II: Non-Recurrent Maps
The pressure function p(t) of a non-recurrent map is real analytic on some interval (0,t_*) with t_* strictly greater than the dimension of the Julia set. The proof is an adaptation of the well known tower techniques to the complex dynamics situation. In general, p(t) need not be analytic on the whole positive axis
Signum Function Method for Generation of Correlated Dichotomic Chains
We analyze the signum-generation method for creating random dichotomic
sequences with prescribed correlation properties. The method is based on a
binary mapping of the convolution of continuous random numbers with some
function originated from the Fourier transform of a binary correlator. The goal
of our study is to reveal conditions under which one can construct binary
sequences with a given pair correlator. Our results can be used in the
construction of superlattices and waveguides with selective transport
properties.Comment: 14 pages, 7 figure
Nanoscopy of pairs of atoms by fluorescence in a magnetic field
Spontaneous emission spectra of two initially excited closely spaced
identical atoms are very sensitive to the strength and the direction of the
applied magnetic field. The relevant schemes are considered that ensure the
determination of the mutual spatial orientation of the atoms and the distance
between them by entirely optical means. A corresponding theoretical description
is given accounting for the dipole-dipole interaction between the two atoms in
the presence of a magnetic field and for polarizations of the quantum field
interacting with magnetic sublevels of the two-atom system
Canonical Representatives of Morphic Permutations
An infinite permutation can be defined as a linear ordering of the set of
natural numbers. In particular, an infinite permutation can be constructed with
an aperiodic infinite word over as the lexicographic order
of the shifts of the word. In this paper, we discuss the question if an
infinite permutation defined this way admits a canonical representative, that
is, can be defined by a sequence of numbers from [0, 1], such that the
frequency of its elements in any interval is equal to the length of that
interval. We show that a canonical representative exists if and only if the
word is uniquely ergodic, and that is why we use the term ergodic permutations.
We also discuss ways to construct the canonical representative of a permutation
defined by a morphic word and generalize the construction of Makarov, 2009, for
the Thue-Morse permutation to a wider class of infinite words.Comment: Springer. WORDS 2015, Sep 2015, Kiel, Germany. Combinatorics on
Words: 10th International Conference. arXiv admin note: text overlap with
arXiv:1503.0618
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