502 research outputs found
Generalized Density Matrix Revisited: Microscopic Approach to Collective Dynamics in Soft Spherical Nuclei
The generalized density matrix (GDM) method is used to calculate
microscopically the parameters of the collective Hamiltonian. Higher order
anharmonicities are obtained consistently with the lowest order results, the
mean field [Hartree-Fock-Bogoliubov (HFB) equation] and the harmonic potential
[quasiparticle random phase approximation (QRPA)]. The method is applied to
soft spherical nuclei, where the anharmonicities are essential for restoring
the stability of the system, as the harmonic potential becomes small or
negative. The approach is tested in three models of increasing complexity: the
Lipkin model, model with factorizable forces, and the quadrupole plus pairing
model.Comment: submitted to Physical Review C on 08 May, 201
New global stability estimates for monochromatic inverse acoustic scattering
We give new global stability estimates for monochromatic inverse acoustic
scattering. These estimates essentially improve estimates of [P. Hahner, T.
Hohage, SIAM J. Math. Anal., 33(3), 2001, 670-685] and can be considered as a
solution of an open problem formulated in the aforementioned work
Spectroscopic studies of fractal aggregates of silver nanospheres undergoing local restructuring
We present an experimental spectroscopic study of large random colloidal
aggregates of silver nanoparticles undergoing local restructuring. We argue
that such well-known phenomena as strong fluctuation of local electromagnetic
fields, appearance of "hot spots" and enhancement of nonlinear optical
responses depend on the local structure on the scales of several nanosphere
diameters, rather that the large-scale fractal geometry of the sample.Comment: 3.5 pages, submitted to J. Chem. Phy
Scientifically-Methodical Bases of Tax Planning in Industrial Complex of Large City
Considered questions of tax revenue planning from large city industrial plants for the example of Saint Petersburg. Investigated the primary factors that influence to the formation the tax base of industrial complexes. Disclosed the peculiarities of planning revenues from sources such as the income tax, property organizations. Characterized the problems which are connected with the tax effect on the development and competitiveness of enterprises. Proposed algorithms for calculating tax revenue
Hopf Structure and Green Ansatz of Deformed Parastatistics Algebras
Deformed parabose and parafermi algebras are revised and endowed with Hopf
structure in a natural way.
The noncocommutative coproduct allows for construction of parastatistics
Fock-like representations, built out of the simplest deformed bose and fermi
representations. The construction gives rise to quadratic algebras of deformed
anomalous commutation relations which define the generalized Green ansatz.Comment: 14 pages, final versio
Bulk-boundary correspondence in three dimensional topological insulators
We discuss the relation between bulk topological invariants and the spectrum
of surface states in three dimensional non-interacting topological insulators.
By studying particular models, and considering general boundary conditions for
the electron wavefunction on the crystal surface, we demonstrate that using
experimental techniques that probe surface states, only strong topological and
trivial insulating phases can be distinguished; the latter state being
equivalent to a weak topological insulator. In a strong topological insulator,
only the {\it parity} of the number of surface states, but not the number
itself, is robust against time-reversal invariant boundary perturbations. Our
results suggest a \z definition of the bulk-boundary correspondence,
compatible with the \z classification of topological insulators.Comment: TeXLive (Unix), revtex4-1, 7 pages, 3 figure
Lateral distribution of high energy muons in EAS of sizes Ne approximately equals 10(5) and Ne approximately equals 10(6)
Muon energy spectra and muon lateral distribution in EAS were investigated with the underground magnetic spectrometer working as a part of the extensive air showers (EAS) array. For every registered muon the data on EAS are analyzed and the following EAS parameters are obtained, size N sub e, distance r from the shower axis to muon, age parameter s. The number of muons with energy over some threshold E associated to EAS of fixed parameters are measured, I sub reg. To obtain traditional characteristics, muon flux densities as a function of the distance r and muon energy E, muon lateral distribution and energy spectra are discussed for hadron-nucleus interaction model and composition of primary cosmic rays
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