11 research outputs found
The Logarithmic Sobolev Constant of The Lamplighter
We give estimates on the logarithmic Sobolev constant of some finite
lamplighter graphs in terms of the spectral gap of the underlying base. Also,
we give examples of application
Continuité-Sobolev de certains opérateurs paradifférentiels.
L'objet de ce travail est l'étude de la continuité des opérateurs d'intégrales singulières (au sens de Calderón-Zygmund) sur les espaces de Sobolev Hs. Il complète le travail fondamental de David-Journé [6], concernant le cas s = 0, et ceux de P. G. Lemarié [10] et M. Meyer [11] concernant le cas 0 < s < 1
Regularity properties of singular integral operators
For s>0, we consider bounded linear operators from into whose kernels K satisfy the conditions
for x≠y, |γ|≤ [s]+1,
for |γ|=[s], x≠y.
We establish a new criterion for the boundedness of these operators from into the homogeneous Sobolev space . This is an extension of the well-known T(1) Theorem due to David and Journé. Our arguments make use of the function T(1) and the BMO-Sobolev space. We give some applications to the Besov and Triebel-Lizorkin spaces as well as some other potential spaces
The Characterization of the Regularity of the Jacobian Determinant in the framework of Bessel Potential Spaces on Domains
Let 2 m n. We give necessary and sufficient conditions on the parameters s 1 ; s 2 ; : : : ; s m ; p 1 ; p 2 ; : : : ; pm such that the Jacobian determinant extends to a bounded operator from H s1 p1 \Theta H s2 p2 \Theta : : : \Theta H sm pm into S 0 . Here all spaces are defined on R n or on domains\Omega ae R n . In almost all cases the regularity of the Jacobian determinant is calculated exactly
Compter et mesurer. Réflexions sur Le souci du nombre dans l'évaluation de la production du savoir scientifique.
10 pages.Dans ce texte, nous cherchons à apporter quelques éléments de réflexion sur la bibliométrie et ses conséquences