共查询到20条相似文献,搜索用时 140 毫秒
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Jia-zu Zhou 《中国科学A辑(英文版)》2007,50(3):325-333
Let ∑ be a convex hypersurface in the Euclidean space R4 with mean curvature H. We obtain a geometric lower bound for the Willmore functional f∑ H2dσ. This bound is an invariant involving the area of ∑, the volume and Minkowski quermassintegrals of the convex body that ∑bounds. We also obtain a sufficient condition for a convex body to contain another in the Euclidean space R4. 相似文献
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The three numbers 1, 5, 10 have the property that the product of any two numbers decreased by 1 is a perfect square. In this paper it is proved that there is no other positive integer N which shares this property with 1, 5, and 10. 相似文献
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Aurel J Zajta 《Journal of Number Theory》1975,7(4):357-360
This paper presents a complete and symmetric solution of the diophantine equation of the title in terms of four parameters α, β, γ, δ, subject to α + β + γ + δ = 0. 相似文献
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Mao Hua LE 《数学学报(英文版)》2008,24(6):917-924
Let a, b and c be fixed coprime positive integers. In this paper we prove that if a^2 + b^2 = c^3 and b is an odd prime, then the equation a^x + b^y = c^z has only the positive integer solution (x, y, z) = (2,2,3). 相似文献
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Nicholas Tzanakis 《Journal of Number Theory》1982,15(3):376-387
It is proved that the equation of the title has a finite number of integral solutions (x, y, n) and necessary conditions are given for (x, y, n) in order that it can be a solution (Theorem 2). It is also proved that for a given odd x0 there is at most one integral solution (y, n), n ≥ 3, to x03 + 3y3 = 2n and for a given odd y0 there is at most one integral solution (x, n), n ≥ 3, to x3 + 3y03 = 2n. 相似文献
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本文给出行列式Vn-(x1,...,xn)的准确值,它是通常的Vandermode行列式计算公式的推广,以及它在理论上的一些重要应用. 相似文献
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Horst von Lienen 《Journal of Number Theory》1978,10(1):10-15
Using known properties of continued fractions, we give a very simple and elementary proof of the theorem of Epstein and Rédei on the impossibility in a certain case of representing ?1 by the quadratic form x2 ? 2py2. Two of our theorems, which concern the representation of a2 and ?2a2, serve to extend our method to an unknown case in which ?1 is not representable. 相似文献
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The simplest case of Fermat's last theorem, the impossibility of solving x3 + y3 = z3 in nonzero integers, has been proved. In other words, 1 is not expressible as a sum of two cubes of rational numbers. However, the slightly extended problem, in which integers D are expressible as a sum of two cubes of rational numbers, is unsolved. There is the conjecture (based on work of Birch, Swinnerton-Dyer, and Stephens) that x3 + y3 = D is solvable in the rational numbers for all square-free positive integers D ≡ 4 (mod 9). The condition that D should be square-free is necessary. As an example, it is shown near the end of this paper that x3 + y3 = 4 has no solutions in the rational numbers. The remainder of this paper is concerned with the proof published by the first author (Proc. Nat. Acad. Sci. USA., 1963) entitled “Remarks on a conjecture of C. L. Siegel.” This pointed out an error in a statement of Siegel that the diophantine equation ax3 + bx2y + cxy2 + dy3 = n has a bounded number of integer solutions for fixed a, b, c, d, and, further, that the bound is independent of a, b, c, d, and n. However, x3 + y3 = n already has an unbounded number of solutions. The paper of S. Chowla itself contains an error or at least an omission. This can be rectified by quoting a theorem of E. Lutz. 相似文献
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Let a, b, c be nonzero integers having no prime factors ≡ 3 (mod 4), not all of the same sign, abc squarefree, and for which Legendre's equation ax2 + by2 + cz2 = 0 is solvable in nonzero integers x, y, z. A property is proved yielding a congruence which must be satisfied by any solution x, y, z. 相似文献
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By means of a new technique of integral representations in C
n
given by the authors, we establish a new abstract formula with a vector function W for smooth functions on bounded domains in C
n
, which is different from the well-known Leray formula. This new formula eliminates the term that contains the parameter A
from the classical Leray formula, and especially on some domains the uniform estimates for the
are very simple. From the new Leray formula, we can obtain correspondingly many new formulas for smooth functions on many
domains in C
n
, which are different from the classical ones, when we properly select the vector function W. 相似文献
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For any complcx λ≠integral, and any natural number n, the product is calcuated and Hadmard''s finite part of obtained. The product is also obtained when λ+μ is a complex number of any other possible kind, and μ is a complex number ≠ integral. The products are also calculated. Any special example of these kinds of products has not yet been calculated. 相似文献
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Nicholas Tzanakis 《Journal of Number Theory》1984,18(2):192-205
The diophantine equation of the title has been solved by Ljunggren, by indirect use of the p-adic method (use is made of intermediate algebraic extensions). It is generally accepted that an immediate application of the p-adic method for the aforementioned equation is impossible. In this paper, however, this view was overthrown by first solving x2 + 3 = 4y3 and then x3 ? 3xy2 ? y3 = 1 with direct application of the p-adic method, avoiding the use of intermediate algebraic extensions, fulfilling thus a desire of Professor Mordell. The method used in this paper has a general character, as it is shown in Appendix B, where three more examples are given. 相似文献
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Using the maximal function characterization of Hardy spaces,we study the interpolation spaces between H^1 and L^∞on spaces of homogeneous type. 相似文献
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Pierre Bousquet 《Journal d'Analyse Mathématique》2007,102(1):311-346
We are interested in the location of the singularities of maps u ∈ W
s,p
(S
N
, S
1) when 1 ≤ sp and 1 < sp < 2. To this end, we consider the distributional Jacobian. We show that the range of this operator on W
s,p
(S
N
, S
1) is the closure in W
s−2,p
⋂ W
−1,sp
of the set of N − 2-currents defined as the integration on smooth oriented N − 2-dimensional boundaryless submanifolds. 相似文献