共查询到20条相似文献,搜索用时 31 毫秒
1.
A Property of <Emphasis Type="Italic">g</Emphasis>-Expectation 总被引:6,自引:0,他引:6
LongJIANG 《数学学报(英文版)》2004,20(5):769-778
This paper proves that, under the hypothesis g(t, 0, 0) ≡ 0 and some natural assumptions, the generator g of a backward stochastic differential equation can be uniquely determined by the corresponding g-expectations with all terminal conditions. The main result of this paper also confirms and extends Peng Shige‘s conjecture. 相似文献
2.
3.
We give a tauberian theorem for boundary values of analytic functions. We prove that if is the distributional limit of the analytic function F defined in a region of the form (a, b) × (0, R), if F (x
0 + iy)→ γ as y → 0+, and if f is distributionally bounded at x = x
0, then f (x
0) = γ distributionally. As a consequence of our tauberian theorem, we obtain a new proof of a tauberian theorem of Hardy and
Littlewood.
Received: 10 December 2007 相似文献
4.
Y. V. Kurylev 《Journal of Mathematical Sciences》1996,79(4):1231-1246
In this paper a uniqueness theorem is proved for the wave equation in the domain Q2T=Ω×(0,2T), where Ω is a piecewise analytic Riemannian manifold (Riemannian polyhedron). Initial data are assumed to be given
on a part Γ0 × (0, 2T) of the space-time boundary of the cylinder Q2T, Γ0. The uniqueness of a weak solution is proved “in the large,” in a domain formed by the corresponding characteristics of the
wave equation. Bibliography:24 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 203, 1992, pp. 113–136.
Translated by T. N. Surkova. 相似文献
5.
In this article, we introduce a nonlinear expectation, called g*-expectation, based on g-expectation and consider the optimal utility under g*-expectation in the market with a risk-free bond and d risky stocks in finite trading interval [0, T]. We construct a stochastic family by taking advantage of the comparison theorem of backward stochastic differential equations and the g*-martingale. We generalize the results of Hu et al. (Annals of Applied Probability 28(2):1691–1712, 2005), and obtain the explicit forms of the optimal trading strategies both for exp?-utility and the power utility, when g(t, z) = βt|z|2 + γtz. 相似文献
6.
LuCHUANRONG 《高校应用数学学报(英文版)》1997,12(4):375-380
Let(x1,j≥1)be a sequence of negatively associated random variables with ex1=o,ex^21<∞.in this paper a functional central limit theorem for negatively associated random variables under some conditions withbout stationarity is proved which is the same as the results for positively associated random variables. 相似文献
7.
Paul C. Fife 《Annali di Matematica Pura ed Applicata》1971,90(1):99-147
Summary The paper treats elliptic operators of the form L(ɛ∂1, ..., ɛ∂n), where L is a polynomial in a variables of order 2m1, and ɛ is a small parameter. Solutionsu
ɛ of Lu=0 in a half space satisfyng conditions Bj(ɛ∂1, ɛ∂2, ..., ɛ∂n)u=ɛγjϕj(x)(j=1, ..., m1) on the boundary are constructed and estimated using H?lder norms, Poisson kernels, and an elaborate potential theory. Properties
of the interior limit u0=u
ɛ(κ) are studied. The paper is preparatory to a detailed investigation of Schauder estimates for such problems with variables
coefficients.
Supported in part by N. S. F. Grant GP-11660.
Entrata in Redazione il 9 gennaio 1971. 相似文献
8.
E is a Banach lattice that is weakly sequentially complete and has a weak unitu. TLf
n=ϕ means that the infimum of |f
n−ϕ| andu converges strongly to zero.T is a positive contraction operator onE andA
n=(1/n)(I+T+...+T
n−1). Without an additional assumption onE, the “truncated limit” TLA
nf need not exist forf inE. This limit exists for eachf ifE satisfies the following additional assumption (C): For everyf inE
+ and for every numberα>0, there is a numberβ=β(f, α) such that ifg is inE
+, ‖g‖≦1, 0≦f′≦f and ‖f′‖>α then ‖f′+g‖≧‖g‖+β.
Research of this author is partially supported by NSERC Grant A3974.
Research of this author is partially supported by NSF Grant 8301619. 相似文献
9.
T. V. Dudnikova 《Theoretical and Mathematical Physics》2011,169(3):1668-1682
We study the dynamics of lattice systems in ℤd, d ≥ 1. We assume that the initial data are random functions. We introduce the family of initial measures {μ0ɛ, ɛ > 0}. The measures μ0ɛ are assumed to be locally homogeneous or “slowly changing” under spatial shifts of the order o(ɛ−1
) and inhomogeneous under shifts of the order ɛ−1
. Moreover, correlations of the measures μ0ɛ decrease uniformly in ɛ at large distances. For all τ ∈ ℝ \ 0, r ∈ ℝd, and κ > 0, we consider distributions of a random solution at the instants t = τ/ɛκ at points close to [r/ɛ] ∈ ℤd. Our main goal is to study the asymptotic behavior of these distributions as ɛ → 0 and to derive the limit hydrodynamic equations of the Euler and Navier-Stokes type. 相似文献
10.
Ulrich Krengel 《Israel Journal of Mathematics》1987,58(2):193-197
It is shown that the pointwise ergodic theorem for Markov operators inL
1, having a finite invariant measure, fails to extend to the case of nonlinear operators.
Recall thatT is called nonexpansive inL
p
if ‖Tf – Tg ‖
p
≦‖f – g‖
p
holds for allf andg. 相似文献
11.
In this paper, a weak Cartan-type second theorem for holomorphic curve f : C→P^n(C) intersecting hypersurfaces Dj, 1≤j≤q, in P^n(C) in general position with degree dj is given as follows: For every ε〉0, there exists a positive integer M such that ||(q - (n + 1) ε)Tf(r)≤∑j^q=1 1/dj Nf^M(r,Dj)+o(Tf(r)), where "||" means the estimate holds for all large r outside a set of finite Lebesgue measure. 相似文献
12.
We consider the collision dynamics produced by three beads with masses (m
1, m
2, m
3) sliding without friction on a ring, where the masses are scaled so that m
1 = 1/ɛ, m
2 = 1, m
3 = 1 − ɛ, for 0 ⩽ ɛ ⩾ 1. The singular limits ɛ = 0 and ɛ = 1 correspond to two equal mass beads colliding on the ring with a wall, and without a wall respectively. In both these
cases, all solutions are periodic and the eigenvalue distributions (around the unit circle) associated with the products of
collision matrices are discrete. We then numerically examine the regime which parametrically connects these two states, i.e.
0 < ɛ < 1, and show that the eigenvalue distribution is generically uniform around the unit circle, which implies that the dynamics
are no longer periodic. By a sequence of careful numerical experiments, we characterize how the uniform spectrum collapses
from continuous to discrete in the two singular limits ɛ → 0 and ɛ → 1 for an ensemble of initial velocities sampled uniformly on a fixed energy surface. For the limit ɛ → 0, the distribution forms Gaussian peaks around the discrete limiting values ± 1, ± i, with variances that scale in power law form as σ
2 ∼ αɛ
β. By contrast, the convergence in the limit ɛ → 1 to the discrete values ±1 is shown to follow a logarithmic power-law σ
2 ∼ log(ɛ
β). 相似文献
13.
LongJiang 《应用数学学报(英文版)》2004,20(4):701-706
With the help of a limit property of solutions of backward stochastic differential equations(BSDEs),this paper establishes a converse comparison theorem for deterministic generators g of BSDEs under the assumption g(t, y, 0) ≡0. 相似文献
14.
K. A. Kopotun 《Constructive Approximation》2001,17(2):307-317
One of the main results of this paper is the following Whitney theorem of interpolatory type for k-monotone functions (i.e., functions f such that divided differences f[x
0,…, x
k
] are nonnegative for all choices of (k + 1) distinct points x
0,…, x
k
. 相似文献
15.
Gilbert Levitt 《Commentarii Mathematici Helvetici》1994,69(1):28-38
LetG be a finitely generated group acting on anR-treeT. First assume that the action is free, and minimal (there is no proper invariant subtree), or more generally that it satisfies
a certain finiteness condition. Then it may be described as agraph of transitive actions: the action may be recovered from a finite graph, together with additional data; in particular, every vertexv carries an action (G
v, Tv) whose orbits are dense. For the action (G, T), it follows for instance that the closure of any orbit is a discrete union of closed subtrees: it cannot meet a segment
in a Cantor set.
Now let ℓ be the length function for an arbitrary action ofG. For ɛ>0 small enough, the subgroupG(ɛ)⊂G generated by elementsg withg is independent of ɛ, andG/G(ɛ) is free. Several interpretations are given for the rank ofG/G(ɛ). 相似文献
16.
Central limit theorem for integrated square error of kernel estimators of spherical density 总被引:1,自引:0,他引:1
LetX
1,…,X
n
be iid observations of a random variableX with probability density functionf(x) on the q-dimensional unit sphere Ωq in Rq+1,q ⩾ 1. Let
be a kernel estimator off(x). In this paper we establish a central limit theorem for integrated square error off
n
under some mild conditions. 相似文献
17.
CHEN Xiaowu HUANG Hualin & ZHANG Pu Department of Mathematics University of Science Technology of China Hefei China USTC Shanghai Institute for Advanced Studies Shanghai China Mathematical Section the Abdus Salam ICTP Strada Costiera Trieste Italy Department of Mathematics Shanghai Jiao Tong University Shanghai China 《中国科学A辑(英文版)》2006,49(1):9-26
18.
TieXin Guo 《中国科学A辑(英文版)》2008,51(9):1651-1663
Let (Ω,A,μ) be a probability space, K the scalar field R of real numbers or C of complex numbers,and (S,X) a random normed space over K with base (ω,A,μ). Denote the support of (S,X) by E, namely E is the essential supremum of the set {A ∈ A: there exists an element p in S such that X
p
(ω) > 0 for almost all ω in A}. In this paper, Banach-Alaoglu theorem in a random normed space is first established as follows: The random closed unit
ball S
*(1) = {f ∈ S
*: X
*
f
⩽ 1} of the random conjugate space (S
*,X
*) of (S,X) is compact under the random weak star topology on (S
*,X
*) iff E∩A=: {E∩A | A ∈ A} is essentially purely μ-atomic (namely, there exists a disjoint family {A
n
: n ∈ N} of at most countably many μ-atoms from E ∩ A such that E = ∪
n=1∞
A
n
and for each element F in E ∩ A, there is an H in the σ-algebra generated by {A
n
: n ∈ N} satisfying μ(FΔH) = 0), whose proof forces us to provide a key topological skill, and thus is much more involved than the corresponding
classical case. Further, Banach-Bourbaki-Kakutani-Šmulian (briefly, BBKS) theorem in a complete random normed module is established
as follows: If (S,X) is a complete random normed module, then the random closed unit ball S(1) = {p ∈ S: X
p
⩽ 1} of (S,X) is compact under the random weak topology on (S,X) iff both (S,X) is random reflexive and E ∩ A is essentially purely μ-atomic. Our recent work shows that the famous classical James theorem still holds for an arbitrary
complete random normed module, namely a complete random normed module is random reflexive iff the random norm of an arbitrary
almost surely bounded random linear functional on it is attainable on its random closed unit ball, but this paper shows that
the classical Banach-Alaoglu theorem and BBKS theorem do not hold universally for complete random normed modules unless they
possess extremely simple stratification structure, namely their supports are essentially purely μ-atomic. Combining the James
theorem and BBKS theorem in complete random normed modules leads directly to an interesting phenomenum: there exist many famous
classical propositions that are mutually equivalent in the case of Banach spaces, some of which remain to be mutually equivalent
in the context of arbitrary complete random normed modules, whereas the other of which are no longer equivalent to another
in the context of arbitrary complete random normed modules unless the random normed modules in question possess extremely
simple stratification structure. Such a phenomenum is, for the first time, discovered in the course of the development of
random metric theory. 相似文献
19.
Jipu Ma 《Frontiers of Mathematics in China》2008,3(2):305-316
Let E and F be Banach spaces, f: U ⊂ E → F be a map of C
r
(r ⩾ 1), x
0 ∈ U, and ft (x
0) denote the FréLechet differential of f at x
0. Suppose that f′(x
0) is double split, Rank(f′(x
0)) = ∞, dimN(f′(x
0)) > 0 and codimR(f′(x
0)) s> 0. The rank theorem in advanced calculus asks to answer what properties of f ensure that f(x) is conjugate to f′(x
0) near x
0. We have proved that the conclusion of the theorem is equivalent to one kind of singularities for bounded linear operators,
i.e., x
0 is a locally fine point for f′(x) or generalized regular point of f(x); so, a complete rank theorem in advanced calculus is established, i.e., a sufficient and necessary condition such that the
conclusion of the theorem to be held is given.
相似文献
20.
Suppose μ is a Radon measure on ℝ
d
, which may be non doubling. The only condition assumed on μ is a growth condition, namely, there is a constant C0>0 such that for all x∈supp(μ) and r>0, μ(B(x, r))⪯C0rn, where 0<n⪯d. We prove T1 theorem for non doubling measures with weak kernel conditions. Our approach yields new results
for kernels satisfying weakened regularity conditions, while recovering previously known Tolsa’s results. We also prove T1
theorem for Besov spaces on nonhomogeneous spaces with weak kernel conditions given in [7]. 相似文献