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Related papers: A simple proof of the $A_2$ conjecture

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This paper is devoted to the study of propagation phenomena for $2$--hyponormal, quadratically hyponormal, and cubically hyponormal operator-valued weighted shifts. \ First, we show that every {\it quadratically} hyponormal matrix-valued…

Functional Analysis · Mathematics 2026-05-12 Raul E. Curto , Abderrazzak Ech-charyfy , Hamza El Azhar , El Hassan Zerouali

The Alperin weight conjecture was reduced to simple groups by the work of Navarro, Tiep and Sp\"ath. To prove Alperin weight conjecture, it suffices to show that all finite non-abelian simple groups are BAW-good. We reduce the verification…

Representation Theory · Mathematics 2022-07-12 Zhicheng Feng , Zhenye Li , Jiping Zhang

In [R2] and [RO] the Arnold conjecture for closed symplectic manifolds with trivial second homotopy group was proved. This proof used surgery and cobordism theory. Here we give a purely cohomological proof of this result.

Differential Geometry · Mathematics 2007-05-23 Yuli B. Rudyak

For a general Calderon-Zygmund operator $T$ on $R^N$, it is shown that $\|Tf\|_{L^2(w)}\leq C(T)\|w\|_{A_2}\|f\|_{L^2(w)}$ for all Muckenhoupt weights $w\in A_2$. This optimal estimate was known as the $A_2$ conjecture. A recent result of…

Classical Analysis and ODEs · Mathematics 2010-07-27 Tuomas P. Hytönen

We give a shorter proof to a recent result by Neuberger, in the real case. Our result is essentially an application of the global asymptotic stability Jacobian Conjecture. We also extend some of the results presented in Neuberger.

Algebraic Geometry · Mathematics 2009-03-27 Marco Sabatini

We study jointly quasinormal and spherically quasinormal pairs of commuting operators on Hilbert space, as well as their powers. We first prove that, up to a constant multiple, the only jointly quasinormal $2$-variable weighted shift is the…

Functional Analysis · Mathematics 2019-10-22 Raul E. Curto , Sang Hoon Lee , Jasang Yoon

Nazarov-Treil-Volberg recently proved an elegant two-weight T1 theorem for "almost diagonal" operators that played a key role in the proof of the $A_2$ conjecture for dyadic shifts and related operators. In this paper, we obtain a…

Classical Analysis and ODEs · Mathematics 2016-10-10 Kelly Bickel , Brett D. Wick

We give new and elementary proofs of one weight norm inequalities for fractional integral operators and commutators. Our proofs are based on the machinery of dyadic grids and sparse operators used in the proof of the A2 conjecture.

Classical Analysis and ODEs · Mathematics 2015-07-10 David Cruz-Uribe

We formulate and study a torsion analogue of the weight-monodromy conjecture for a proper smooth scheme over a non-archimedean local field. We prove it for proper smooth schemes over equal characteristic non-archimedean local fields,…

Number Theory · Mathematics 2020-08-28 Kazuhiro Ito

Let $\mathbf{A}$ be a bounded self-adjoint operator on a separable Hilbert space $\mathfrak{H}$ and $\mathfrak{H}_0\subset\mathfrak{H}$ a closed invariant subspace of $\mathbf{A}$. Assuming that $\sup\spec(A_0)\leq \inf\spec(A_1)$, where…

Spectral Theory · Mathematics 2007-05-23 Vadim Kostrykin , Konstantin A. Makarov , Alexander K. Motovilov

We give a proof of the $A_2$ conjecture in geometrically doubling metric spaces (GDMS), i.e. a metric space where one can fit not more than a fixed amount of disjoint balls of radius $r$ in a ball of radius $2r$. Our proof consists of three…

Classical Analysis and ODEs · Mathematics 2013-01-11 Fedor Nazarov , Alexander Reznikov , Alexander Volberg

We give a short and simple polynomial estimate of the norm of weighted dyadic shift on metric space with geometric doubling, which is linear in the norm of the weight. Combined with the existence of special probability space of dyadic…

Metric Geometry · Mathematics 2011-04-28 Fedor Nazarov , Alexander Volberg

Let $G$ be a compact, connected simple Lie group and $\mathfrak{g}$ its Lie algebra. It is known that if $\mu $ is any $G$-invariant measure supported on an adjoint orbit in $\mathfrak{g}$, then for each integer $k$, the $k$% -fold…

Classical Analysis and ODEs · Mathematics 2016-12-06 Kathryn Hare , Jimmy He

We prove that if a pair of weights $(u,v)$ satisfies a sharp $A_p$-bump condition in the scale of log bumps and certain loglog bumps, then Haar shifts map $L^p(v)$ into $L^p(u)$ with a constant quadratic in the complexity of the shift. This…

Analysis of PDEs · Mathematics 2013-01-07 David Cruz-Uribe , Alexander Reznikov , Alexander Volberg

We prove a general result implying the $L^2$ stability of Haar decompositions of $L^2({\bf R}^d)$ functions when the Haar functions are distorted by arbitrary, independent, affine changes of variable that are close to the identity. We apply…

Classical Analysis and ODEs · Mathematics 2023-07-26 James Michael Wilson

This exposition presents a self-contained proof of the $A_2$ theorem, the quantitatively sharp norm inequality for singular integral operators in the weighted space $L^2(w)$. The strategy of the proof is a streamlined version of the…

Classical Analysis and ODEs · Mathematics 2019-11-19 Tuomas P. Hytönen

Any Calderon-Zygmund operator T is pointwise dominated by a convergent sum of positive dyadic operators. We give an elementary self-contained proof of this fact, which is simpler than the probabilistic arguments used for all previous…

Classical Analysis and ODEs · Mathematics 2015-09-07 Tuomas P. Hytönen , Michael T. Lacey , Carlos Pérez

We obtain a system of relations between linear Hodge integrals. As an application, we show that its first non-trivial relation implies the Witten's Conjecture/Kontsevich Theorem.

Algebraic Geometry · Mathematics 2007-05-23 Yon-Seo Kim , Kefeng Liu

We prove a local $Tb$ theorem under close to minimal (up to certain `buffering') integrability assumptions, conjectured by S. Hofmann (El Escorial, 2008): Every cube is assumed to support two non-degenerate functions $b^1_Q\in L^p$ and…

Classical Analysis and ODEs · Mathematics 2020-07-10 Tuomas Hytönen , Fedor Nazarov

We prove the conjecture of Friedlander et al. about sums over Littelmann patterns for the the root system of type $G_2$, which is an analogue of Tokuyama's theorem for root systems of type $A_r$. We use elementary means to show that the…

Representation Theory · Mathematics 2018-06-26 Mario DeFranco