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Related papers: Fourier restriction to smooth enough curves

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An improved lower bound is given for the decay of conical averages of Fourier transforms of measures, for cones of dimension $d \geq 4$. The proof uses a weighted version of the broad restriction inequality, a narrow decoupling inequality…

Analysis of PDEs · Mathematics 2019-11-05 Terence L. J. Harris

Let C be a real nonsingular affine curve of genus one, embedded in affine n-space, whose set of real points is compact. For any polynomial f which is nonnegative on C(R), we prove that there exist polynomials f_i with f \equiv \sum_i f_i^2…

Algebraic Geometry · Mathematics 2010-03-25 Claus Scheiderer

We prove moment inequalities for exponential sums with respect to singular measures, whose Fourier decay matches those of curved hypersurfaces. Our emphasis will be on proving estimates that are sharp with respect to the scale parameter…

Classical Analysis and ODEs · Mathematics 2021-05-18 Ciprian Demeter , Bartosz Langowski

In order to compute the Fourier transform of a function $f$ on the real line numerically, one samples $f$ on a grid and then takes the discrete Fourier transform. We derive exact error estimates for this procedure in terms of the decay and…

Numerical Analysis · Mathematics 2025-12-18 Martin Ehler , Karlheinz Gröchenig , Andreas Klotz

We improve the range for the discrete Fourier restriction to the four and five dimensional spheres. We rely on two new ingredients, incidence theory and Siegel's mass formula.

Classical Analysis and ODEs · Mathematics 2013-10-22 Jean Bourgain , Ciprian Demeter

We systematically study weighted $L^2$ restriction for quadratic manifolds of arbitrary codimensions by sharp uniform Fourier decay estimates and a refinement of the Du-Zhang method. Comparison with prior results is also discussed. In…

Classical Analysis and ODEs · Mathematics 2025-06-24 Zhenbin Cao , Jingyue Li , Changxing Miao , Yixuan Pang

The purpose of this note is to discuss several results that have been obtained in the last decade in the context of sharp adjoint Fourier restriction/Strichartz inequalities. Rather than aiming at full generality, we focus on several…

Classical Analysis and ODEs · Mathematics 2017-01-25 Damiano Foschi , Diogo Oliveira e Silva

Let $X$ be a complex affine variety in $\mathbb{C}^N$, and let $f:\mathbb{C}^N\to \mathbb{C}$ be a polynomial function whose restriction to $X$ is nonconstant. For $g:\mathbb{C}^N \to \mathbb{C}$ a general linear function, we study the…

Algebraic Topology · Mathematics 2020-02-04 Laurentiu G. Maxim , Jose Israel Rodriguez , Botong Wang

We consider, for a class of functions $\varphi : \mathbb{R}^{2} \setminus \{ {\bf 0} \} \to \mathbb{R}^{2}$ satisfying a nonisotropic homogeneity condition, the Fourier transform $\hat{\mu}$ of the Borel measure on $\mathbb{R}^{4}$ defined…

Classical Analysis and ODEs · Mathematics 2022-07-21 Tomás Godoy , Pablo Rocha

Let $X$ be an irreducible projective variety of dimension $n$ in a projective space and let $x$ be a point of $X$. Denote by ${\rm Curves}_d(X,x)$ the space of curves of degree $d$ lying on $X$ and passing through $x$. We will show that the…

Algebraic Geometry · Mathematics 2007-05-23 Jun-Muk Hwang

By analyzing the affine Taylor expansion of a non-degenerate plane curve, we obtain characterizations of classes of such curves via curvature properties of the gravity curve. The proof is based on an analysis of the degree parity and…

Differential Geometry · Mathematics 2011-11-01 Thomas Binder

The purpose of this article is to prove a "Newton over Hodge" result for finite characters on curves. Let $X$ be a smooth proper curve over a finite field $\mathbb{F}_q$ of characteristic $p\geq 3$ and let $V \subset X$ be an affine curve.…

Number Theory · Mathematics 2021-07-13 Joe Kramer-Miller

We prove an optimal restriction theorem for an arbitrary homogeneous polynomial hypersurface (of degree at least 2) in R^3, with affine curvature introduced as mitigating factor.

Classical Analysis and ODEs · Mathematics 2011-08-23 A. Carbery , C. Kenig , S. Ziesler

We prove sharp smoothing properties of the averaging operator defined by convolution with a measure on a smooth nondegenerate curve $\gamma$ in $\mathbb R^d$, $d\ge 3$. Despite the simple geometric structure of such curves, the sharp…

Classical Analysis and ODEs · Mathematics 2022-04-01 Hyerim Ko , Sanghyuk Lee , Sewook Oh

We improve the best known exponent for the restriction conjecture in R^6. Our idea is applicable to any dimension n satisfying n = 0 mod 3, though we do not explicitly calculate the improvement for n > 6. This improves the recent results of…

Classical Analysis and ODEs · Mathematics 2012-09-03 Faruk Temur

We introduce a continuous analog of the Fourier ratio for compactly supported Borel measures. For a measure \(\mu\) on \(\mathbb{R}^d\) and \(f\in L^2(\mu)\), the Fourier ratio compares \(L^1\) and \(L^2\) norms of a regularized Fourier…

Classical Analysis and ODEs · Mathematics 2025-12-19 A. Iosevich , Z. Li , E. Palsson , A. Yavicoli

Given a real projective curve with homogeneous coordinate ring R and a nonnegative homogeneous element f in R, we bound the degree of a nonzero homogeneous sum-of-squares g in R such that the product fg is again a sum of squares. Better…

Algebraic Geometry · Mathematics 2019-09-13 Grigoriy Blekherman , Gregory G. Smith , Mauricio Velasco

This is an addendum to the paper of Braun and Fl{\o}ystad ([BF]) on the bound for the degree of a smooth surface in $\pfour$ not of general type. Using their construction and the regularity of curves in $\pthree$, one may lower the bound a…

alg-geom · Mathematics 2015-06-30 Michele Cook

In this paper, we establish a general discrete Fourier restriction theorem. As an application, we make some progress on the discrete Fourier restriction associated with KdV equation.

Analysis of PDEs · Mathematics 2017-10-05 Xudong Lai , Yong Ding

Consider a component of the Hilbert scheme whose general point corresponds to a degree d genus g smooth irreducible and nondegenerate curve in a projective variety X. We give lower bounds for the dimension of such a component when X is P^3,…

Algebraic Geometry · Mathematics 2008-08-28 Dawei Chen