410,377 research outputs found
Bound states of the Klein-Gordon equation for vector and scalar general Hulthen-type potentials in D-dimension
We solve the Klein-Gordon equation in any -dimension for the scalar and
vector general Hulth\'{e}n-type potentials with any by using an
approximation scheme for the centrifugal potential. Nikiforov-Uvarov method is
used in the calculations. We obtain the bound state energy eigenvalues and the
corresponding eigenfunctions of spin-zero particles in terms of Jacobi
polynomials. The eigenfunctions are physical and the energy eigenvalues are in
good agreement with those results obtained by other methods for D=1 and 3
dimensions. Our results are valid for value when and for any
value when and D=1 or 3. The % -wave () binding energies for
a particle of rest mass are calculated for the three lower-lying
states using pure vector and pure scalar potentials.Comment: 25 page
Non-universal size dependence of the free energy of confined systems near criticality
The singular part of the finite-size free energy density of the O(n)
symmetric field theory in the large-n limit is calculated at finite
cutoff for confined geometries of linear size L with periodic boundary
conditions in 2 < d < 4 dimensions. We find that a sharp cutoff
causes a non-universal leading size dependence
near which dominates the universal scaling term . This
implies a non-universal critical Casimir effect at and a leading
non-scaling term of the finite-size specific heat above .Comment: RevTex, 4 page
The Market Fraction Hypothesis under different GP algorithms
In a previous work, inspired by observations made in many agent-based financial models, we formulated and presented the Market Fraction Hypothesis, which basically predicts a short duration for any dominant type of agents, but then a uniform distribution over all types in the long run. We then proposed a two-step approach, a rule-inference step and a rule-clustering step, to testing this hypothesis. We employed genetic programming as the rule inference engine, and applied self-organizing maps to cluster the inferred rules. We then ran tests for 10 international markets and provided a general examination of the plausibility of the hypothesis. However, because of the fact that the tests took place under a GP system, it could be argued that these results are dependent on the nature of the GP algorithm. This chapter thus serves as an extension to our previous work. We test the Market Fraction Hypothesis under two new different GP algorithms, in order to prove that the previous results are rigorous and are not sensitive to the choice of GP. We thus test again the hypothesis under the same 10 empirical datasets that were used in our previous experiments. Our work shows that certain parts of the hypothesis are indeed sensitive on the algorithm. Nevertheless, this sensitivity does not apply to all aspects of our tests. This therefore allows us to conclude that our previously derived results are rigorous and can thus be generalized
Non-adiabatic Fast Control of Mixed States based on Lewis-Riesenfeld Invariant
We apply the inversely-engineered control method based on Lewis-Riesenfeld
invariants to control mixed states of a two-level quantum system. We show that
the inversely-engineered control passages of mixed states - and pure states as
special cases - can be made significantly faster than the conventional
adiabatic control passages, which renders the method applicable to quantum
computation. We devise a new type of inversely-engineered control passages, to
be coined the antedated control passages, which further speed up the control
significantly. We also demonstrate that by carefully tuning the control
parameters, the inversely-engineered control passages can be optimized in terms
of speed and energy cost.Comment: 9 pages, 9 figures, version to appear in J. Phys. Soc. Jp
Cogeneration of Dark Matter and Baryons by Non-Standard-Model Sphalerons in Unified Models
Sphalerons of a new gauge interaction can convert a primordial asymmetry in B
or L into a dark matter asymmetry. From the equilibrium conditions for the
sphalerons of both the electroweak and the new interactions, one can compute
the ratios of B, L, and X, where X is the dark matter number, thus determining
the mass of the dark matter particle fairly precisely. Such a scenario can
arise naturally in the context of unification with larger groups. An
illustrative model embeddable in is described
as well as an equally simple model based on SU(7).Comment: 13 pages. Revised introduction and references, changed titl
Characterization of the 4-canonical birationality of algebraic threefolds
In this article we present a 3-dimensional analogue of a well-known theorem
of E. Bombieri (in 1973) which characterizes the bi-canonical birationality of
surfaces of general type. Let be a projective minimal 3-fold of general
type with -factorial terminal singularities and the geometric genus
. We show that the 4-canonical map is {\it not}
birational onto its image if and only if is birationally fibred by a family
of irreducible curves of geometric genus 2 with
where is a general irreducible member in .Comment: 25 pages, to appear in Mathematische Zeitschrif
Computer program for structural analysis of layered orthotropic ring-stiffened shells of revolution (SALORS): Linear stress analysis option
Program handles segmented, laminar, orthotropic shells with discrete rings. Meridional variations are handled in material properties, temperatures, and wall thickness. Allows for linear variations of temperature through each layer of shell wall
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