Results 21 to 30 of about 63,567 (182)
Mathematische Annalen, 2008 Let $X$ be a projective manifold of dimension $n$ and $L$ a strictly nef line bundle on $X$. Then $K_X+tL$ is ample if $t > n+1$ in the following cases. 1.) $\text{dim} X = 3$ unless (possibly) $X$ is a Calabi-Yau with $c_2 \cdot L=0$; 2.) $ (X) \ge n-2$; 3.) $\text{dim} (X) \ge n-2$, with $ : X \to A$ the Albanese map.
Campana, F., Chen, J.A., Peternell, T.
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Thirty-nine perfect numbers and their divisors
International Journal of Mathematics and Mathematical Sciences, 1986 The following results concerning even perfect numbers and their divisors are proved: (1) A positive integer n of the form 2p−1(2p−1), where 2p−1 is prime, is a perfect number; (2) every even perfect number is a triangular number; (3) τ(n)=2p, where τ(n ...
Syed Asadulla
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Nonnegative Inverse Elementary Divisors Problem for Lists with Nonnegative Real Parts
Mathematics, 2020 In this paper, sufficient conditions for the existence and construction of nonnegative matrices with prescribed elementary divisors for a list of complex numbers with nonnegative real part are obtained, and the corresponding nonnegative matrices are ...
Hans Nina +3 more
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Uniruled Symplectic Divisors [PDF]
Communications in Mathematics and Statistics, 2013 45 ...
Li, Tian-Jun, Ruan, Yongbin
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Journal of Mathematics, 2022 Huppert and Manz have determined the nonsolvable groups whose character degrees are products of at most two prime numbers. In this paper, we change the condition from “degrees of a group are products of at most two prime divisors” to “degrees of all ...
Shitian Liu, Xingzheng Tang
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Divisors and square-free divisors involving the floor function [PDF]
Notes on Number Theory and Discrete MathematicsLet τ(n) (respectively, τ#(n)) be the number of divisors (respectively, square free divisors) of natural number n, and let [t] be the integral part of real number t.
B. Feng, J. Wu
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ON A SUM INVOLVING CERTAIN ARITHMETIC FUNCTIONS ON PIATETSKI–SHAPIRO AND BEATTY SEQUENCES
Проблемы анализа, 2022 Let 𝑐, 𝛼, 𝛽 ∈ R be such that ...
T. Srichan
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Remarks on level one conformal blocks divisors [PDF]
, 2013 We show that conformal blocks divisors of type B_r and D_r at level one are effective sums of boundary divisors of $\bar{M}_{0,n}$. We also prove that the conformal blocks divisor of type $B_r$ at level 1 with weights (\omega_1,\dots,\omega_1) scales ...
Mukhopadhyay, Swarnava
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, 2016 We study a novel type of braid groups on a closed orientable surface $ $. These are fundamental groups of certain manifolds that are hybrids between symmetric products and configuration spaces of points on $ $; a class of examples arises naturally in gauge theory, as moduli spaces of vortices in toric fibre bundles over $ $.
Bökstedt, Marcel, Romão, Nuno Miguel
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Mathematika, 2018 Let $s(\cdot)$ denote the sum-of-proper-divisors function, that is, $s(n) = \sum_{d\mid n ...
Pollack, Paul +2 more
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