917 research outputs found
Türkiye Cumhuriyeti ve halifelik
Taha Toros Arşivi, Dosya Adı: Son Halife Abdülmecit Efendi. Not: Gazetenin "Olaylar ve Görüşler" köşesinde yayımlanmıştır
Coherent States for Generalized Laguerre Functions
We explicitly construct a Hamiltonian whose exact eigenfunctions are the
generalized Laguerre functions. Moreover, we present the related raising and
lowering operators. We investigate the corresponding coherent states by
adopting the Gazeau-Klauder approach, where resolution of unity and overlapping
properties are examined. Coherent states are found to be similar to those found
for a particle trapped in a P\"oschl-Teller potential of the trigonometric
type. Some comparisons with Barut-Girardello and Klauder-Perelomov methods are
noticed.Comment: 12 pages, clarifications and references added, misprints correcte
Flowering Buds of Globular Proteins: Transpiring Simplicity of Protein Organization
Structural and functional complexity of proteins is dramatically reduced to a simple linear picture when the laws of polymer physics are considered. A basic unit of the
protein structure is a nearly standard closed loop of 25–35 amino acid residues, and
every globular protein is built of consecutively connected closed loops. The physical
necessity of the closed loops had been apparently imposed on the early stages of
protein evolution. Indeed, the most frequent prototype sequence motifs in prokaryotic
proteins have the same sequence size, and their high match representatives are found
as closed loops in crystallized proteins. Thus, the linear organization of the closed
loop elements is a quintessence of protein evolution, structure and folding
Barut-Girardello coherent states for u(p,q) and sp(N,R) and their macroscopic superpositions
The Barut-Girardello coherent states (BG CS) representation is extended to
the noncompact algebras u(p,q) and sp(N,R) in (reducible) quadratic boson
realizations. The sp(N,R) BG CS take the form of multimode ordinary
Schr\"odinger cat states. Macroscopic superpositions of 2^{n-1} sp(N,R) CS (2^n
canonical CS, n=1,2,...) are pointed out which are overcomplete in the N-mode
Hilbert space and the relation between the canonical CS and the u(p,q) BG-type
CS representations is established. The sets of u(p,q) and sp(N,R) BG CS and
their discrete superpositions contain many states studied in quantum optics
(even and odd N-mode CS, pair CS) and provide an approach to quadrature
squeezing, alternative to that of intelligent states. New subsets of weakly and
strongly nonclassical states are pointed out and their statistical properties
(first- and second-order squeezing, photon number distributions) are discussed.
For specific values of the angle parameters and small amplitude of the
canonical CS components these states approaches multimode Fock states with one,
two or three bosons/photons. It is shown that eigenstates of a squared
non-Hermitian operator A^2 (generalized cat states) can exhibit squeezing of
the quadratures of A.Comment: 29 pages, LaTex, 5 figures. Improvements in text, corrections in some
formulas. To appear in J. Phys. A, v. 3
Symplectic Partially Hyperbolic Automorphisms of 6-Torus
We study topological properties of automorphisms of a 6-dimensional torus
generated by integer matrices symplectic with respect to either the standard
symplectic structure in six-dimensional linear space or a nonstandard
symplectic structure given by an integer skew-symmetric non-degenerate matrix.
Such a symplectic matrix generates a partially hyperbolic automorphism of the
torus, if it has eigenvalues both outside and on the unit circle. We study the
case (2,2,2), numbers are dimensions of stable, center and unstable subspaces
of the matrix. We study transitive and decomposable cases possible here and
present a classification in both cases.Comment: 15 pages, 0 figures. arXiv admin note: text overlap with
arXiv:2001.1072
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