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

Effects of Sequence Disorder on DNA Looping and Cyclization

Effects of sequence disorder on looping and cyclization of the double-stranded DNA are studied theoretically. Both random intrinsic curvature and inhomogeneous bending rigidity are found to result in a remarkably wide distribution of cyclization probabilities. For short DNA segments, the range of the distribution reaches several orders of magnitude for even completely random sequences. The ensemble averaged values of the cyclization probability are also calculated, and the connection to the recent experiments is discussed.Comment: 8 pages, 4 figures, LaTeX; accepted to Physical Review E; v2: a substantially revised version; v3: references added, conclusions expanded, minor editorial corrections to the text; v4: a substantially revised and expanded version (total number of pages doubled); v5: new Figure 4, captions expanded, minor editorial improvements to the tex

Stretching semiflexible filaments with quenched disorder

We study the effect of quenched randomness in the arc-length dependent spontaneous curvature of a wormlike chain under tension. In the weakly bending approximation in two dimensions, we obtain analytic results for the force-elongation curve and the width of transverse fluctuations. We compare quenched and annealed disorder and conclude that the former cannot always be reduced to a simple change in the stiffness of the pure system. We also discuss the effect of a random transverse force on the stretching response of a wormlike chain without spontaneous curvature.Comment: 5 pages, minor changes, added references, final version as published in PR

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

A 5000-year-old souslik fur garment from an elite megalithic tombe in the North Caucasus, Maykop culture

This paper presents the results of a unique fur garment from the megalithic tomb of a rich man in the Northwest Caucasus, dated to the Early Bronze Age, which was excavated in 1898 (Tsarskaya, Russia). The garment was made from the fur of a souslik group animal, most likely the ground squirrel. Direct radiocarbon dating puts the fur at around 4445 ± 35 BP (ca. 3300-3000 BC), making it the earliest known fur garment in Eastern Europe. The choice of souslik fur stands in direct contrast to widely held views on prestigious fur clothes in traditional and contemporary societies

A 5000-year-old souslik fur garment from an elite megalithic tombe in the North Caucasus, Maykop culture

This paper presents the results of a unique fur garment from the megalithic tomb of a rich man in the Northwest Caucasus, dated to the Early Bronze Age, which was excavated in 1898 (Tsarskaya, Russia). The garment was made from the fur of a souslik group animal, most likely the ground squirrel. Direct radiocarbon dating puts the fur at around 4445 ± 35 BP (ca. 3300-3000 BC), making it the earliest known fur garment in Eastern Europe. The choice of souslik fur stands in direct contrast to widely held views on prestigious fur clothes in traditional and contemporary societies

Management of Corporate Business Process Cost Performance Based on Key Costs Data

One of the most complex problems of implementing corporate process-based management includes arrangements for accounting and analysis of costs related to business process execution. Methods conventionally used to these ends cannot be leveraged in terms of business processes whose cost performance changes dynamically, which is particularly customary for companies in emerging markets. The methods proposed by this article authors are only based on accounting and analysis of most important key costs. In reliance on key costs, one develops an indirect costs exact distribution model, which indirect costs are related to the execution of various business processes. Key costs data is also used to analyze alternatives of cost reduction and risk minimization. This paper offers criteria for qualifying costs as key costs. Fundamental principles have been determined for developing an activity-based costing model based on key costs data, and trends in analysis of key costs have been established. Keywords: Business Process Management, Cost Analysis, Activity-Based Costing. JEL Classifications: D24, M

Purity-bounded uncertainty relations in multidimensional space -- generalized purity

Uncertainty relations for mixed quantum states (precisely, purity-bounded position-momentum relations, developed by Bastiaans and then by Man'ko and Dodonov) are studied in general multi-dimensional case. An expression for family of mixed states at the lower bound of uncertainty relation is obtained. It is shown, that in case of entropy-bounded uncertainty relations, lower-bound state is thermal, and a transition from one-dimensional problem to multi-dimensional one is trivial. Results of numerical calculation of the relation lower bound for different types of generalized purity are presented. Analytical expressions for general purity-bounded relations for highly mixed states are obtained.Comment: 12 pages, 2 figures. draft version, to appear in J. Phys. A Partially based on a poster "Multidimensional uncertainty relations for states with given generalized purity" presented on X Intl. Conf. on Quantum Optics'2004 (Minsk, Belarus, May 30 -- June 3, 2004) More actual report is to be presented on ICSSUR-2005, Besan\c{c}on, France and on EQEC'05, Munich. V. 5: amended article after referees' remark