69,228 research outputs found
Pauli-blocking Effect in a Quark Model
Pauli-Blocking effect on the kinetic term is investigated by employing the
quark cluster model. The effect can be understood by the change of the degrees
of the mixing between the incoming wave and the 0 state of the
inter-cluster wave function, which can be expressed by a potential which is
highly nonlocal. We look into the properties of this effect by comparing
equivalent local potentials. In the channel where the Pauli-blocking effect is
small, the on-shell equivalent local potential simulates the nonlocal potential
well even for the off-shell behavior. On the other hand, the off-shell behavior
is very different from the original one where the effect is large. This
off-shell behavior, however, can well be simulated by considering the nonlocal
matrix elements only between the state and the other states. The energy
dependent potentials are also constructed and found to be helpful to understand
the energy dependence of the effect.Comment: 14 pages, 12 figure
Coincidence sets in quasilinear elliptic problems of monostable type
This paper concerns the formation of a coincidence set for the positive
solution of -Laplacian elliptic problems of monostable type. It is proved
that for any small parameter of diffusion term, the solution coincides with the
stable zero-function of reaction term in an open set if is
-harmonic (but, not constant) and a zero of order less than 1. Inversely, it
is also shown that the solution is less than if is a zero of
order greater than or equal to 1. The proof rely on comparison theorems and an
energy method for obtaining local comaprison functions.Comment: 18 page
Bifurcation values of polynomial functions and perverse sheaves
We characterize bifurcation values of polynomial functions by using the
theory of perverse sheaves and their vanishing cycles. In particular, by
introducing a method to compute the jumps of the Euler characteristics with
compact support of their fibers, we confirm the conjecture of N\'emethi-Zaharia
in many cases.Comment: 19 pages, to appear in Annales de l'Institut Fourie
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