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951.
Lin-Feng Wang 《Annals of Global Analysis and Geometry》2010,37(4):393-402
Let M be an n-dimensional complete non-compact Riemannian manifold, dμ = e
h
(x)dV(x) be the weighted measure and
\trianglem{\triangle_{\mu}} be the weighted Laplacian. In this article, we prove that when the m-dimensional Bakry–émery curvature is bounded from below by Ric
m
≥ −(m − 1)K, K ≥ 0, then the bottom of the Lm2{{\rm L}_{\mu}^2} spectrum λ1(M) is bounded by
l1(M) £ \frac(m-1)2K4,\lambda_1(M) \le \frac{(m-1)^2K}{4}, 相似文献
952.
Stewart Baldwin 《Journal of Fixed Point Theory and Applications》2010,7(1):201-222
We construct abstract Julia sets homeomorphic to Julia sets for complex polynomials of the form f
c
(z) = z
2 + c, having an associated periodic kneading sequence of the form [`(a*)]{\overline{\alpha\ast}} which is not a period n-tupling. We show that there is a single simply-defined space of “itineraries” which contains homeomorphic copies of all such
Julia sets in a natural combinatorial way, with dynamical properties which are derivable directly from the combinatorics.
This also leads to a natural definition of abstract Julia sets even for those kneading sequences which are not realized by
any polynomial f
c
, with similar dynamical properties. 相似文献
953.
954.
It is shown that a cost function subject to internal costs of adjustment induces a stochastic discount factor (pricing kernel)
that is a function of random output, input and output prices, existing capital stock, and investment. The only assumption
on firm preferences is that they are increasing in current period consumption and future stochastic consumption. This ensures
that the firm will always act to minimize current period cost of providing future consumption, and it is the first-order conditions
for this cost minimization problem that generate the stochastic discount factor, which itself can be interpreted as the marginal
variable cost of varying stochastic output. A cost-based pricing kernel is estimated using annual time-series data on macroeconomic
variables and returns data for the S&P 500 and commercial paper. 相似文献
955.
Valdis Laan 《Periodica Mathematica Hungarica》2010,60(1):81-94
Two semigroups are called strongly Morita equivalent if they are contained in a Morita context with unitary bi-acts and surjective
mappings. We consider the notion of context equivalence which is obtained from the notion of strong Morita equivalence by
dropping the requirement of unitariness. We show that context equivalence is an equivalence relation on the class of factorisable
semigroups and describe factorisable semigroups that are context equivalent to monoids or groups, and semigroups with weak
local units that are context equivalent to inverse semigroups, orthodox semigroups or semilattices. 相似文献
956.
With the application of the topological upgrade, more and more experts are interested in the problems concerning the mathematical
structure’s upgrade to its power set. This paper is a further study on the structure and interrelationship of a power group.
By revealing the nature of relationship between the power group and a regular one, the present paper proves some theorems
of the structure of the power group and constructs some theorems on its homomorphism and isomorphism as well, proposing an
expression form and isomorphism replacement construct methods of the power group. 相似文献
957.
The main aim of this paper is to prove the existence and uniqueness of the solution for neutral stochastic functional differential
equations with infinite delay, which the initial data belong to the phase space ℬ((−∞,0];ℝ
d
). The vital work of this paper is to extend the initial function space of the paper (Wei and Wang, J. Math. Anal. Appl. 331:516–531,
2007) and give some examples to show that the phase space ℬ((−∞,0];ℝ
d
) exists. In addition, this paper builds a Banach space ℳ2((−∞,T],ℝ
d
) with a new norm in order to discuss the existence and uniqueness of the solution for such equations with infinite delay. 相似文献
958.
Won Keun Min 《Acta Mathematica Hungarica》2010,129(4):350-356
We introduce the notion of (δ,δ′)-continuous functions on generalized topological spaces and investigate characterizations for such functions. We study the
relationship between (δ,δ′)-continuity and several types of continuity on generalized topological spaces. 相似文献
959.
Armin Lechleiter 《BIT Numerical Mathematics》2010,50(1):59-83
We consider imaging of periodic penetrable structures from measurements of scattered electromagnetic waves. The importance
of this problem stems from the decreasing size of periodic structures in photonic devices, together with an increasing demand
in fast non-destructive testing. This demand makes qualitative inverse scattering techniques particularly attractive since
they do not use time consuming optimization techniques for reconstruction but rather directly transform measured data into
a picture of the scattering object. We present the Factorization method as an algorithm for imaging of a special class of
periodic dielectric structures known as diffraction gratings. Our sampling method computes a picture of the shape of the periodic
structure from measured near-field data in a rapid way. We provide numerical examples illustrating this imaging technique. 相似文献
960.
In this note we investigate the asymptotic behavior of the solutions of the heat equation with random, fast oscillating potential
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