Let b be aBMO-function. It is well-known that the linear commutator [b, T ] of a Calderón-Zygmund operator T does not, in general, map continuously H(R) into L(R). However, Pérez showed that if H(R) is replaced by a suitable atomic subspace H b(R ) then the commutator is continuous from H b(R ) into L(R). In this paper, we find the largest subspace H b (R ) such that all commutators of Calderón...

We present a local exponential fitting hybridized mixed finiteelement method for convection-diffusion problem on a bounded domain with mixed Dirichlet Neuman boundary conditions. With a new technique that interpretes the algebraic system after static condensation as a bilinear form acting on certain lifting operators we prove an a priori error estimate on the Lagrange multipliers that requires ...

We present the main ideas of the proof of the following result: The characteristic function of the unit disc in R is the symbol of a bounded bilinear multiplier operator from L1(R) × L2(R) into L(R) when 2 ≤ p1, p2 < ∞ and 1 < p = p1p2 p1+p2 ≤ 2.

In this article, we consider an analogue of Kenig and Stein's bilinear fractional integral operator on the Heisenberg group Hn. We completely characterize exponents α,β γ such that is bounded from Lp(Hn,|x|αp)×Lq(Hn,|x|βq) to Lr(Hn,|x|−γr). Also, analogous sharp results are obtained Euclidean space.

(defined for Schwarzt test functions f and g in ) extends to a bounded bilinear operator from Lp1 (R)×Lp2 (R) into Lp3 (R). The theory of these multipliers has been tremendously developed after the results proved by Lacey and Thiele (see [16, 18, 17]) which establish that m(ξ,ν) = sign(ξ +αν) is a (p1, p2)-multiplier for each triple (p1, p2, p3) such that 1 < p1, p2 ≤∞, p3 > 2/3, and each α∈R \...

A difference analogue of the logistic equation, which preserves integrability, is derived from Hirota’s bilinear difference equation. The integrability of the map is shown to result from the large symmetry associated with the Bäcklund transformation of the KP hierarchy. We introduce a scheme which interpolates between this map and the standard logistic map and enables us to study integrable and...

Let X ,Z be a pair of real linear spaces put in duality by a separating bilinear form 〈, 〉, and endowed with compatible locally convex topologies respectively. A subset F of X is said to be p-bounded if sup p(x) : x ∈ F < ∞. We denote the collection of all nonempty p-bounded subsets of X by p(X ). Given x ∈ X , F ∈ p(X ), and V ⊆ X , write rp(F ; x) = sup p(y − x) : y ∈ F , radp(F ;V ) = inf rp...

Let V be a Hilbert space, a(·, ·) : V × V → lR a bounded, V-elliptic bilinear form and : V → lR a bounded linear functional. We want to approximate the variational equation: Find u ∈ V such that (3.1) a(u, v) = (v) , v ∈ V. We recall that the Lax-Milgram Lemma ensures the existence and uniqueness of a solution of (3.1). Now, given a finite-dimensional subspace V h ⊂ V , dim V h = n h , the Ritz...

The paper introduces k-bounded MAP inference, a parameterization of MAP inference in Markov logic networks. k-Bounded MAP states are MAP states with at most k active ground atoms of hidden (non-evidence) predicates. We present a novel delayed column generation algorithm and provide empirical evidence that the algorithm efficiently computes k-bounded MAP states for meaningful real-world graph ma...