Restrictions of Fourier transforms to curves

S. W. Drury

Displaying similar documents to “Restrictions of Fourier transforms to curves”

General-affine invariants of plane curves and space curves

Shimpei Kobayashi, Takeshi Sasaki (2020)

Czechoslovak Mathematical Journal

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We present a fundamental theory of curves in the affine plane and the affine space, equipped with the general-affine groups $GA (2) = GL (2, ℝ) ⋉ ℝ^{2}$ and $GA (3) = GL (3, ℝ) ⋉ ℝ^{3}$ , respectively. We define general-affine length parameter and curvatures and show how such invariants determine the curve up to general-affine motions. We then study the extremal problem of the general-affine length functional and derive a variational formula. We give several examples of curves and also discuss some relations with equiaffine treatment and...

Complex orientation formulas for $M$ -curves of degree $4 d + 1$ with 4 nests

S.Yu. Orevkov (2010)

Annales de la faculté des sciences de Toulouse Mathématiques

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On démontre la formule d’orientations complexes pour les $M$ -courbes dans ${ℝ P}^{2}$ de degré $4 d + 1$ ayant $4$ nids. Cette formule généralise celle pour les $M$ -courbes à nid profond. C’est un pas vers la classification des $M$ -courbes de degré $9$ .

Timelike $B_{2}$ -slant helices in Minkowski space $E_{1}^{4}$

Ahmad T. Ali, Rafael López (2010)

Archivum Mathematicum

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We consider a unit speed timelike curve $α$ in Minkowski 4-space $𝐄_{1}^{4}$ and denote the Frenet frame of $α$ by ${𝐓, 𝐍, 𝐁_{1}, 𝐁_{2}}$ . We say that $α$ is a generalized helix if one of the unit vector fields of the Frenet frame has constant scalar product with a fixed direction $U$ of $𝐄_{1}^{4}$ . In this work we study those helices where the function $〈 𝐁_{2}, U 〉$ is constant and we give different characterizations of such curves.

A differential equation related to the $l^{p}$ -norms

Jacek Bojarski, Tomasz Małolepszy, Janusz Matkowski (2011)

Annales Polonici Mathematici

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Let p ∈ (1,∞). The question of existence of a curve in ℝ₊² starting at (0,0) and such that at every point (x,y) of this curve, the $l^{p}$ -distance of the points (x,y) and (0,0) is equal to the Euclidean length of the arc of this curve between these points is considered. This problem reduces to a nonlinear differential equation. The existence and uniqueness of solutions is proved and nonelementary explicit solutions are given.

On the arithmetic of the hyperelliptic curve $y^{2} = x^{n} + a$

Kevser Aktaş, Hasan Şenay (2016)

Czechoslovak Mathematical Journal

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We study the arithmetic properties of hyperelliptic curves given by the affine equation $y^{2} = x^{n} + a$ by exploiting the structure of the automorphism groups. We show that these curves satisfy Lang’s conjecture about the covering radius (for some special covering maps).

Optimal curves differing by a 5-isogeny

Dongho Byeon, Taekyung Kim (2014)

Acta Arithmetica

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For i = 0,1, let $E_{i}$ be the $X_{i} (N)$ -optimal curve of an isogeny class of elliptic curves defined over ℚ of conductor N. Stein and Watkins conjectured that E₀ and E₁ differ by a 5-isogeny if and only if E₀ = X₀(11) and E₁ = X₁(11). In this paper, we show that this conjecture is true if N is square-free and is not divisible by 5. On the other hand, Hadano conjectured that for an elliptic curve E defined over ℚ with a rational point P of order 5, the 5-isogenous curve E’ := E/⟨P⟩ has a rational...

An iterative construction for ordinary and very special hyperelliptic curves

Francis J. Sullivan (1983)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

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Si costruiscono famiglie di curve iperellittiche col $p$ —rango della varietà jacobiana uguale a zero. La costruzione sfrutta le proprietà elementari dell’operatore di Cartier e delle estensioni $p$ -cicliche dei corpi con la caratteristica $p$ maggiore di zero.

A group law on smooth real quartics having at least $3$ real branches

Johan Huisman (2002)

Journal de théorie des nombres de Bordeaux

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Let $C$ be a smooth real quartic curve in $ℙ^{2}$ . Suppose that $C$ has at least $3$ real branches $B_{1}, B_{2}, B_{3}$ . Let $B = B_{1} \times B_{2} \times B_{3}$ and let $O \in B$ . Let $τ_{O}$ be the map from $B$ into the neutral component Jac $(C) {(ℝ)}^{0}$ of the set of real points of the jacobian of $C$ , defined by letting $τ_{O} (P)$ be the divisor class of the divisor $\sum P_{i} - O_{i}$ . Then, $τ_{O}$ is a bijection. We show that this allows an explicit geometric description of the group law on Jac $(C) {(ℝ)}^{0}$ . It generalizes the classical geometric description of the group law on the neutral component of the set of real...

A Remark on a Paper of Crachiola and Makar-Limanov

Robert Dryło (2011)

Bulletin of the Polish Academy of Sciences. Mathematics

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A. Crachiola and L. Makar-Limanov [J. Algebra 284 (2005)] showed the following: if X is an affine curve which is not isomorphic to the affine line $¹_{k}$ , then ML(X×Y) = k[X]⊗ ML(Y) for every affine variety Y, where k is an algebraically closed field. In this note we give a simple geometric proof of a more general fact that this property holds for every affine variety X whose set of regular points is not k-uniruled.

Osculating curves in 4-dimensional semi-Euclidean space with index 2

Kazim İlarslan, Nihal Kiliç, Hatice Altin Erdem (2017)

Open Mathematics

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In this paper, we give the necessary and sufficient conditions for non-null curves with non-null normals in 4-dimensional Semi-Euclidian space with indeks 2 to be osculating curves. Also we give some examples of non-null osculating curves in [...] E24 $𝔼_{2}^{4}$ .