2,769 research outputs found
Multistable behavior above synchronization in a locally coupled Kuramoto model
A system of nearest neighbors Kuramoto-like coupled oscillators placed in a
ring is studied above the critical synchronization transition. We find a
richness of solutions when the coupling increases, which exists only within a
solvability region (SR). We also find that they posses different
characteristics, depending on the section of the boundary of the SR where the
solutions appear. We study the birth of these solutions and how they evolve
when {K} increases, and determine the diagram of solutions in phase space.Comment: 8 pages, 10 figure
Electrically Induced Morphological Instabilities in Free Dendrite Growth
We describe a new instability mechanism in free dendrite growth, which arises from electrically enhanced diffusion of polar molecules near the dendrite tip. For a small applied potential, the dendrite tip velocity increases slowly with potential, as is described by an extension of normal solvability theory. Above a threshold potential, however, capillarity is insufficient to stabilize growth. We present observations that confirm this instability, which brings about a transition from enhanced normal dendrite growth to a rapidly growing needle morphology with strongly suppressed sidebranching
Solvability of eigenvalues in jn configurations
Eigenvalues of eigenstates in jn configurations (n identical nucle- ons in
the j -orbit) are functions of two-body energies. In some cases they are linear
combinations of two-body energies whose coe+/-cients are independent of the
interaction and are rational non-negative num- bers. It is shown here that a
state which is an eigenstate of any two-body interaction has this solvability
property. This includes, in particular, any state with spin J if there are no
other states with this J in the jn configuration. It is also shown that
eigenstates with solvable eigenvalues have definite seniority v and thus,
exhibit partial dynamical symmetry
Test of Guttmann and Enting's conjecture in the eight-vertex model
We investigate the analyticity property of the partially resummed series
expansion(PRSE) of the partition function for the eight-vertex model.
Developing a graphical technique, we have obtained a first few terms of the
PRSE and found that these terms have a pole only at one point in the complex
plane of the coupling constant. This result supports the conjecture proposed by
Guttmann and Enting concerning the ``solvability'' in statistical mechanical
lattice models.Comment: 15 pages, 3 figures, RevTe
Why do firms borrow on a short-term basis ? Evidence from European countries
This paper investigates empirically the use of short-term bank loans by firms. We face two analytical frameworks. According to the corporate finance theory, short-term and long-term ebts are substitutes, while in the credit channel literature they are distinct and complementary vehicles. We estimate a model that explains the level of short-term bank debt, using panel data from the BACH database for six European countries (1989-2003). Our results indicate that the two types of bank loans are complements. They show that short-term bank debt should be analysed as a specific vehicle that finances current assets, as in the credit channel literature.corporate short-term debt, debt maturity structure, credit channel
Cloud chambers and crystal growth:âEffects of electrically enhanced diffusion on dendrite formation from neutral molecules
We present an extension of the solvability theory for free dendrite growth that includes the effects of electrically enhanced diffusion of neutral polar molecules. Our theory reveals a new instability mechanism in free dendrite growth, which arises when electrically enhanced diffusion near the dendrite tip overwhelms the stabilizing influence of surface tension. This phenomenon is closely related to the growth instability responsible for the visualization of charged particle tracks in cloud chambers, and is expected for enhanced diffusion of neutral molecules, but not for the case of ionic diffusion. Above a threshold applied potential, the crystal growth can no longer be described by the usual solvability theory, and requires a new physical mechanism to limit the growth velocity. We also describe experimental observations of the free dendrite growth of ice crystals from water vapor in supersaturated normal air. These observations demonstrate the calculated growth instability, which results in the rapid growth of branchless ice needles with a tip velocity 5â50 times the normal dendrite tip velocity. The production of clean ice needles is useful for the study of ice crystal growth from vapor, allowing the controlled growth of isolated single-crystal samples. This instability mechanism may find further application in crystal growth from a wide variety of polar molecules
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