arXiv subjects

V. Felouzis

Publications and source records attributed to V. Felouzis.

3 recordsLinked to original sources

arXiv2026

Lattices which can be represented as lattices of intervals

We investigate the representation of lattices as sublattices of the lattice of all convex subsets (intervals) of a linearly ordered set $(X,\le)$. We introduce the purely lattice-theoretic notion of a \textit{loc-lattice} and prove that every loc-lattice is representable as a lattice of intervals. Furthermore, we provide the complete, unabridged construction for the general representation theorem, establishing that a well-separated lattice is faithfully representable as a lattice of intervals if and only if it is a loc-lattice. Finally, we apply these results to general topology, obtaining novel algebraic characterizations for the bases of weakly orderable and completely orderable topological spaces.

math.GM↗

arXiv2008

S-numbers of elementary operators on C*-algebras

We study the s-numbers of elementary operators acting on C*-algebras. The main results are the following: If $τ$ is any tensor norm and $a,b\in B(H)$ are such that the sequences $s(a),s(b)$ of their singular numbers belong to a stable Calkin space $J$ then the sequence of approximation numbers of $a\otimes_τ b$ belongs to $J$. If $A$ is a C*-algebra, $J$ is a stable Calkin space, $s$ is an s-number function, and $a_i, b_i \in A,$ $i=1,...,m$ are such that $s(π(a_i)), s(π(b_i)) \in J$, $i=1,...,m$ for some faithful representation $π$ of $A$ then $s(\sum_{i=1}^{m} M_{a_i,b_i})\in J$. The converse implication holds if and only if the ideal of compact elements of $A$ has finite spectrum. We also prove a quantitative version of a result of Ylinen.

math.OA↗

arXiv1997

Interpolating hereditarily indecomposable Banach spaces

It is shown that every Banach space either contains $\ell ^1$ or it has an infinite dimensional closed subspace which is a quotient of a H.I. Banach space.Further on, $L^p(λ)$, $1<p<\infty $, is a quotient of a H.I Banach space.

math.FA↗