Recent Developments in the Theory of Lorentz Spaces and Weighted Inequalities

Recent Developments in the Theory of Lorentz Spaces and Weighted Inequalities PDF Author: María J. Carro
Publisher: American Mathematical Soc.
ISBN: 0821842374
Category : Mathematics
Languages : en
Pages : 146

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Book Description
The main objective of this work is to bring together two well known and, a priori, unrelated theories dealing with weighted inequalities for the Hardy-Littlewood maximal operator $M$. for this, the authors consider the boundedness of $M$ in the weighted Lorentz space $\Lambdap u(w)$. Two examples are historically relevant as a motivation: If $w=1$, this corresponds to the study of the boundedness of $M$ on $Lp(u)$, which was characterized by B. Muckenhoupt in 1972, and the solution is given by the so called $A p$ weights. The second case is when we take $u=1$. This is a more recent theory, and was completely solved by M.A. Arino and B. Muckenhoupt in 1991. It turns out that the boundedness of $M$ on $\Lambdap(w)$ can be seen to be equivalent to the boundedness of the Hardy operator $A$ restricted to decreasing functions of $Lp(w)$, since the nonincreasing rearrangement of $Mf$ is pointwise equivalent to $Af*$. The class of weights satisfying this boundedness is known as $B p$. Even though the $A p$ and $B p$ classes enjoy some similar features, they come from very different theories, and so are the techniques used on each case: Calderon-Zygmund decompositions and covering lemmas for $A p$, rearrangement invariant properties and positive integral operators for $B p$. This work aims to give a unified version of these two theories. Contrary to what one could expect, the solution is not given in terms of the limiting cases above considered (i.e., $u=1$ and $w=1$), but in a rather more complicated condition, which reflects the difficulty of estimating the distribution function of the Hardy-Littlewood maximal operator with respect to general measures.

Recent Developments in the Theory of Lorentz Spaces and Weighted Inequalities

Recent Developments in the Theory of Lorentz Spaces and Weighted Inequalities PDF Author: María J. Carro
Publisher: American Mathematical Soc.
ISBN: 0821842374
Category : Mathematics
Languages : en
Pages : 146

Get Book Here

Book Description
The main objective of this work is to bring together two well known and, a priori, unrelated theories dealing with weighted inequalities for the Hardy-Littlewood maximal operator $M$. for this, the authors consider the boundedness of $M$ in the weighted Lorentz space $\Lambdap u(w)$. Two examples are historically relevant as a motivation: If $w=1$, this corresponds to the study of the boundedness of $M$ on $Lp(u)$, which was characterized by B. Muckenhoupt in 1972, and the solution is given by the so called $A p$ weights. The second case is when we take $u=1$. This is a more recent theory, and was completely solved by M.A. Arino and B. Muckenhoupt in 1991. It turns out that the boundedness of $M$ on $\Lambdap(w)$ can be seen to be equivalent to the boundedness of the Hardy operator $A$ restricted to decreasing functions of $Lp(w)$, since the nonincreasing rearrangement of $Mf$ is pointwise equivalent to $Af*$. The class of weights satisfying this boundedness is known as $B p$. Even though the $A p$ and $B p$ classes enjoy some similar features, they come from very different theories, and so are the techniques used on each case: Calderon-Zygmund decompositions and covering lemmas for $A p$, rearrangement invariant properties and positive integral operators for $B p$. This work aims to give a unified version of these two theories. Contrary to what one could expect, the solution is not given in terms of the limiting cases above considered (i.e., $u=1$ and $w=1$), but in a rather more complicated condition, which reflects the difficulty of estimating the distribution function of the Hardy-Littlewood maximal operator with respect to general measures.

Differential Geometry, Lie Groups and Symmetric Spaces over General Base Fields and Rings

Differential Geometry, Lie Groups and Symmetric Spaces over General Base Fields and Rings PDF Author: Wolfgang Bertram
Publisher: American Mathematical Soc.
ISBN: 0821840916
Category : Mathematics
Languages : en
Pages : 218

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Book Description
The aim of this work is to lay the foundations of differential geometry and Lie theory over the general class of topological base fields and -rings for which a differential calculus has been developed, without any restriction on the dimension or on the characteristic. Two basic features distinguish the author's approach from the classical real (finite or infinite dimensional) theory, namely the interpretation of tangent- and jet functors as functors of scalar extensions and the introduction of multilinear bundles and multilinear connections which generalize the concept of vector bundles and linear connections.

Multi-Pulse Evolution and Space-Time Chaos in Dissipative Systems

Multi-Pulse Evolution and Space-Time Chaos in Dissipative Systems PDF Author: Sergey Zelik
Publisher: American Mathematical Soc.
ISBN: 0821842641
Category : Mathematics
Languages : en
Pages : 112

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Book Description
The authors study semilinear parabolic systems on the full space ${\mathbb R}^n$ that admit a family of exponentially decaying pulse-like steady states obtained via translations. The multi-pulse solutions under consideration look like the sum of infinitely many such pulses which are well separated. They prove a global center-manifold reduction theorem for the temporal evolution of such multi-pulse solutions and show that the dynamics of these solutions can be described by an infinite system of ODEs for the positions of the pulses. As an application of the developed theory, The authors verify the existence of Sinai-Bunimovich space-time chaos in 1D space-time periodically forced Swift-Hohenberg equation.

Extended Abstracts 2021/2022

Extended Abstracts 2021/2022 PDF Author: Michael Ruzhansky
Publisher: Springer Nature
ISBN: 3031425391
Category :
Languages : en
Pages : 302

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Book Description


Limit Theorems of Polynomial Approximation with Exponential Weights

Limit Theorems of Polynomial Approximation with Exponential Weights PDF Author: Michael I. Ganzburg
Publisher: American Mathematical Soc.
ISBN: 0821840630
Category : Mathematics
Languages : en
Pages : 178

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Book Description
The author develops the limit relations between the errors of polynomial approximation in weighted metrics and apply them to various problems in approximation theory such as asymptotically best constants, convergence of polynomials, approximation of individual functions, and multidimensional limit theorems of polynomial approximation.

Torus Fibrations, Gerbes, and Duality

Torus Fibrations, Gerbes, and Duality PDF Author: Ron Donagi
Publisher: American Mathematical Soc.
ISBN: 0821840924
Category : Mathematics
Languages : en
Pages : 104

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Book Description
Let $X$ be a smooth elliptic fibration over a smooth base $B$. Under mild assumptions, the authors establish a Fourier-Mukai equivalence between the derived categories of two objects, each of which is an $\mathcal{O} DEGREES{\times}$ gerbe over a genus one fibration which is a twisted form

Rank One Higgs Bundles and Representations of Fundamental Groups of Riemann Surfaces

Rank One Higgs Bundles and Representations of Fundamental Groups of Riemann Surfaces PDF Author: William Mark Goldman
Publisher: American Mathematical Soc.
ISBN: 082184136X
Category : Mathematics
Languages : en
Pages : 86

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Book Description
This expository article details the theory of rank one Higgs bundles over a closed Riemann surface $X$ and their relation to representations of the fundamental group of $X$. The authors construct an equivalence between the deformation theories of flat connections and Higgs pairs. This provides an identification of moduli spaces arising in different contexts. The moduli spaces are real Lie groups. From each context arises a complex structure, and the different complex structures define a hyperkähler structure. The twistor space, real forms, and various group actions are computed explicitly in terms of the Jacobian of $X$. The authors describe the moduli spaces and their geometry in terms of the Riemann period matrix of $X$.

Complicial Sets Characterising the Simplicial Nerves of Strict $\omega $-Categories

Complicial Sets Characterising the Simplicial Nerves of Strict $\omega $-Categories PDF Author: Dominic Verity
Publisher: American Mathematical Soc.
ISBN: 0821841424
Category : Mathematics
Languages : en
Pages : 208

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Book Description
The primary purpose of this work is to characterise strict $\omega$-categories as simplicial sets with structure. The author proves the Street-Roberts conjecture in the form formulated by Ross Street in his work on Orientals, which states that they are exactly the ``complicial sets'' defined and named by John Roberts in his handwritten notes of that title (circa 1978). On the way the author substantially develops Roberts' theory of complicial sets itself and makes contributions to Street's theory of parity complexes. In particular, he studies a new monoidal closed structure on the category of complicial sets which he shows to be the appropriate generalisation of the (lax) Gray tensor product of 2-categories to this context. Under Street's $\omega$-categorical nerve construction, which the author shows to be an equivalence, this tensor product coincides with those of Steiner, Crans and others.

Galois Extensions of Structured Ring Spectra/Stably Dualizable Groups

Galois Extensions of Structured Ring Spectra/Stably Dualizable Groups PDF Author: John Rognes
Publisher: American Mathematical Soc.
ISBN: 0821840762
Category : Mathematics
Languages : en
Pages : 154

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Book Description
The author introduces the notion of a Galois extension of commutative $S$-algebras ($E_\infty$ ring spectra), often localized with respect to a fixed homology theory. There are numerous examples, including some involving Eilenberg-Mac Lane spectra of commutative rings, real and complex topological $K$-theory, Lubin-Tate spectra and cochain $S$-algebras. He establishes the main theorem of Galois theory in this generality. Its proof involves the notions of separable and etale extensions of commutative $S$-algebras, and the Goerss-Hopkins-Miller theory for $E_\infty$ mapping spaces. He shows that the global sphere spectrum $S$ is separably closed, using Minkowski's discriminant theorem, and he estimates the separable closure of its localization with respect to each of the Morava $K$-theories. He also defines Hopf-Galois extensions of commutative $S$-algebras and studies the complex cobordism spectrum $MU$ as a common integral model for all of the local Lubin-Tate Galois extensions. The author extends the duality theory for topological groups from the classical theory for compact Lie groups, via the topological study by J. R. Klein and the $p$-complete study for $p$-compact groups by T. Bauer, to a general duality theory for stably dualizable groups in the $E$-local stable homotopy category, for any spectrum $E$.

Brownian Brownian Motion-I

Brownian Brownian Motion-I PDF Author: Nikolai Chernov
Publisher: American Mathematical Soc.
ISBN: 082184282X
Category : Science
Languages : en
Pages : 208

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Book Description
A classical model of Brownian motion consists of a heavy molecule submerged into a gas of light atoms in a closed container. In this work the authors study a 2D version of this model, where the molecule is a heavy disk of mass $M \gg 1$ and the gas is represented by just one point particle of mass $m=1$, which interacts with the disk and the walls of the container via elastic collisions. Chaotic behavior of the particles is ensured by convex (scattering) walls of the container. The authors prove that the position and velocity of the disk, in an appropriate time scale, converge, as $M\to\infty$, to a Brownian motion (possibly, inhomogeneous); the scaling regime and the structure of the limit process depend on the initial conditions. The proofs are based on strong hyperbolicity of the underlying dynamics, fast decay of correlations in systems with elastic collisions (billiards), and methods of averaging theory.