183 research outputs found
Global well-posedness of the Kirchhoff equation and Kirchhoff systems
This article is devoted to review the known results on global well-posedness
for the Cauchy problem to the Kirchhoff equation and Kirchhoff systems with
small data. Similar results will be obtained for the initial-boundary value
problems in exterior domains with compact boundary. Also, the known results on
large data problems will be reviewed together with open problems.Comment: arXiv admin note: text overlap with arXiv:1211.300
Local well-posedness for the space-time Monopole equation in Lorenz gauge
It is known from the work of Czubak that the space-time Monopole equation is
locally well-posed in the Coulomb gauge for small initial data in
for . Here we prove local well-posedness for
arbitrary initial data in with in the Lorenz gauge.Comment: To appear in NoDE
Dispersive estimates for Schr\"odinger operators with point interactions in
The study of dispersive properties of Schr\"odinger operators with point
interactions is a fundamental tool for understanding the behavior of many body
quantum systems interacting with very short range potential, whose dynamics can
be approximated by non linear Schr\"odinger equations with singular
interactions. In this work we proved that, in the case of one point interaction
in , the perturbed Laplacian satisfies the same
estimates of the free Laplacian in the smaller regime . These
estimates are implied by a recent result concerning the boundedness of
the wave operators for the perturbed Laplacian. Our approach, however, is more
direct and relatively simple, and could potentially be useful to prove optimal
weighted estimates also in the regime .Comment: To appear on: "Advances in Quantum Mechanics: Contemporary Trends and
Open Problems", G. Dell'Antonio and A. Michelangeli eds., Springer-INdAM
series 201
L^p boundedness of the wave operator for the one dimensional Schroedinger operator
Given a one dimensional perturbed Schroedinger operator H=-(d/dx)^2+V(x) we
consider the associated wave operators W_+, W_- defined as the strong L^2
limits as s-> \pm\infty of the operators e^{isH} e^{-isH_0} We prove that the
wave operators are bounded operators on L^p for all 1<p<\infty, provided
(1+|x|)^2 V(x) is integrable, or else (1+|x|)V(x) is integrable and 0 is not a
resonance. For p=\infty we obtain an estimate in terms of the Hilbert
transform. Some applications to dispersive estimates for equations with
variable rough coefficients are given.Comment: 26 page
Interpolation Theorems for Self-adjoint Operators
We prove a complex and a real interpolation theorems on Besov spaces and
Triebel-Lizorkin spaces associated with a selfadjoint operator , without
assuming the gradient estimate for its spectral kernel. The result applies to
the cases where is a uniformly elliptic operator or a Schr\"odinger
operator with electro-magnetic potential.Comment: 8 pages. Submitte
A time-frequency analysis perspective on Feynman path integrals
The purpose of this expository paper is to highlight the starring role of
time-frequency analysis techniques in some recent contributions concerning the
mathematical theory of Feynman path integrals. We hope to draw the interest of
mathematicians working in time-frequency analysis on this topic, as well as to
illustrate the benefits of this fruitful interplay for people working on path
integrals.Comment: 26 page
Michael Gove’s war on professional historical expertise : conservative curriculum reform, extreme Whig history and the place of imperial heroes in modern multicultural Britain
Six years of continuously baiting his opponents within the history profession eventually amounted to little where it mattered most. UK Secretary of State for Education, Michael Gove, finally backtracked in 2013 on his plans to impose a curriculum for English schools based on a linear chronology of the achievements of British national heroes. His ‘history as celebration’ curriculum was designed to instil pride amongst students in a supposedly shared national past, but would merely have accentuated how many students in modern multicultural Britain fail to recognise themselves in what is taught in school history lessons. Now that the dust has settled on Gove’s tenure as Secretary of State, the time is right for retrospective analysis of how his plans for the history curriculum made it quite so far. How did he construct an ‘ideological’ conception of expertise which allowed him to go toe-to-toe for so long with the ‘professional’ expertise of academic historians and history teachers? What does the content of this ideological expertise tell us about the politics of race within Conservative Party curriculum reforms? This article answers these questions to characterise Gove as a ‘whig historian’ of a wilfully extreme nature in his attachment to imperial heroes as the best way to teach national history in modern multicultural Britain
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