The sum of squares of degrees of bipartite graphsActa Mathematica Academiae Scientiarum Hungarica - Tập 171 - Trang 1-11 - 2023
M. G. Neubauer
Let G be a subgraph of the complete bipartite graph
$$K_{l,m},{l \leq m}$$
, with
$$e=qm+p>0$$
,
$$0 \leq p ... hiện toàn bộ
The Number of Compatible Totally Bounded Quasi-UniformitiesActa Mathematica Academiae Scientiarum Hungarica - Tập 88 - Trang 15-23 - 2000
H.-P. A. Künzi, M. J. Pérez-Peñalver
We prove that a topological space that admits a nontransitive totally bounded quasi-uniformity, admits at least
$$2^{2^{N_0 } } $$
nontransitive totally bounded quasi-uniformities. Furthermore we show that each infinite T
2-space admits at least
...... hiện toàn bộ
Some functional equations on standard operator algebrasActa Mathematica Academiae Scientiarum Hungarica - Tập 118 - Trang 299-306 - 2007
A. Fošner, J. Vukman
The main purpose of this paper is to prove the following result. Let H be a complex Hilbert space, let
$$
\mathcal{B}
$$
(H) be the algebra of all bounded linear operators on H, and let
$$
\mathcal{A}
$$
(H) ⊂
...... hiện toàn bộ
Ideals inZ[x, y]Acta Mathematica Academiae Scientiarum Hungarica - Tập 32 Số 1-2 - Trang 63-73 - 1978
Peter Trotter
Walsh series and measureActa Mathematica Academiae Scientiarum Hungarica - Tập 102 Số 3 - Trang 261-267 - 2004
Yoneda, Kaoru
Let ξ =(ξ0,ξ1,...) be a zero-one series. We shall study whether the Walsh series, $$\sum\limits_{n = 0}^\infty {\xi _n } w_n (x)$$ is the Walsh--Fourier series of some measure or not.
Special forms and the distribution of practical numbersActa Mathematica Academiae Scientiarum Hungarica - Tập 160 - Trang 405-411 - 2019
X.-H. Wu
A positive integer n is called practical if every positive integer $$m \leq n$$ can be written as a sum of distinct divisors of n. For any integers $$a, b, k > 0$$, we show that if $$2 \nmid a$$, then there are infinitely many nonnegative integers m such that $$am^{k} + bm^{k-1}$$ is practical. Let qn denote the n-th practical number. Further, when $$n \geq 7$$, we prove that $$\sqrt{q_{n}+1} - \s...... hiện toàn bộ