Аннотация:
In this paper we show that the set of all elements $g\in L^p(\mathcal{H})$ for which $(|g|*|g|)(x)<\infty$ for
a center element $x\in B$, is $\sigma$-$c$-lower porous, where $p > 2$, $\mathcal{H}$ is a non-compact unimodular hypergroup
and $B$ is some special symmetric compact neighborhood of the identity element. As an application, we
give some new equivalent condition for the finiteness of a discrete Hermitian hypergroup. Moreover,
we give some sufficient conditions for the set of all pairs $(f, g)$ in $L^p(\mathcal{H})\times L^q(\mathcal{H})$ for which for a
center element $x\in B$, $(|f|*|g|)(x)<\infty$, is a $\sigma$-$c$-lower porous, where $p, q > 1$ with $\frac1p+\frac1q<1$. Also,
we show that the complement of this set is spaceable in $L^p(\mathcal{H})\times L^q(\mathcal{H})$.
Ключевые слова и фразы:locally compact hypergroup, center of hypergroups, porosity, $\sigma$-lower porosity, spaceability, Lebesgue spaces, Hilbert spaces, convolution.