activity
20112025
most citedInterpretable groups are definable

3 citations · 8 across the 13 of their papers we have counts for

collaborators

23 papers

math.LO2025

On the global linear Zarankiewicz problem

Pantelis E. Eleftheriou, Aris Papadopoulos

The `global' Zarankiewicz problem for hypergraphs asks for an upper bound on the number of edges of a finite -hypergraph in terms of the number of its vertices, assumi…

math.LO2025

Orthogonality and domination in o-minimal expansions of ordered groups

Pablo Andújar Guerrero, Pantelis E. Eleftheriou, Rosario Mennuni

We analyse domination between invariant types in o-minimal expansions of ordered groups, showing that the domination poset decomposes as the direct product of two posets: the domin…

math.CO2025

Exact VC-Dimensions of Certain Geometric Set Systems

Pantelis E. Eleftheriou, Aris Papadopoulos, Francis Westhead

The VC-dimension of a family of sets is a measure of its combinatorial complexity used in machine learning theory, computational geometry, and even model theory. Computing the VC-d…

math.LO2021

Orthogonal decomposition of definable groups

Alessandro Berarducci, Pantelis E. Eleftheriou, Marcello Mamino

Orthogonality in model theory captures the idea of absence of non-trivial interactions between definable sets. We introduce a somewhat opposite notion of cohesiveness, capturing th…

math.LO2020

Groups definable in weakly o-minimal non-valuational structures

Pantelis E. Eleftheriou

Let be a weakly o-minimal non-valuational structure, and its canonical o-minimal extension (by Wencel). We prove that every group definable in $\mathc…

math.LO2020

On semibounded expansions of ordered groups

Pantelis E. Eleftheriou, Alex Savatovsky

We explore "semibounded" expansions of arbitrary ordered groups; namely, expansions that do not define a field on the whole universe. We show that if $\mathcal R=\langle R, <, +, \…

math.LO2020

Coincidence of dimensions in closed ordered differential fields

Pantelis E. Eleftheriou, Omar Leon Sanchez, Nathalie Regnault

Let be a closed ordered differential field, in the sense of M. Singer, and its field of constants. In this note, we prove that, for set…

math.LO2018★ 2 cited

Expansions of real closed fields which introduce no new smooth functions

Pantelis E. Eleftheriou, Alex Savatovsky

We prove the following theorem: let be an expansion of the real field , such that every definable set (I) is a uniform countable unio…

math.LO2018

Small sets in Mann pairs

Pantelis E. Eleftheriou

Let be an expansion of a real closed field by a dense subgroup of with the Man…

math.LO2018

Locally definable subgroups of semialgebraic groups

Elías Baro, Pantelis E. Eleftheriou, Ya'acov Peterzil

We prove the following instance of a conjecture stated in arXiv:1103.4770. Let be an abelian semialgebraic group over a real closed field and let be a semialgebraic sub…

math.LO2018

Strongly minimal groups in o-minimal structures

Pantelis Eleftheriou, Assaf Hasson, Ya'acov Peterzil

We prove Zilber's Trichotomy Conjecture for strongly minimal expansions of two-dimensional groups, definable in o-minimal structures: Theorem. Let M be an o-minimal expansion of a…

math.LO2018

Characterizing o-minimal groups in tame expansions of o-minimal structures

Pantelis E. Eleftheriou

We establish the first global results for groups definable in tame expansions of o-minimal structures. Let be an expansion of an o-minimal structure that…

math.LO2017

The Choice Property in tame expansions of o-minimal structures

Pantelis E. Eleftheriou, Ayhan Günaydın, Philipp Hieronymi

We establish the choice property, a weak analogue of definable choice, for certain tame expansions of o-minimal structures. Most noteworthily, dense pairs of real closed fields hav…

math.LO2017

Product cones in dense pairs

Pantelis E. Eleftheriou

Let be an o-minimal expansion of an ordered group, and a dense set such that certain tameness conditions hold. We introduc…

math.LO2017

Counting algebraic points in expansions of o-minimal structures by a dense set

Pantelis E. Eleftheriou

The Pila-Wilkie theorem states that if a set is definable in an o-minimal structure and contains `many' rational points, then it contains an i…

math.LO2017

Small sets in dense pairs

Pantelis E. Eleftheriou

Let be an expansion of an o-minimal structure by a dense set , such that three tameness conditions…

math.LO2016

Semi-linear stars are contractible

Pantelis E. Eleftheriou

Let be an ordered vector space over an ordered division ring. We prove that every definable set is a finite union of relatively open definable subsets which are defina…

math.LO2015

Structure theorems in tame expansions of o-minimal structures by a dense set

Pantelis E. Eleftheriou, Ayhan Günaydin, Philipp Hieronymi

We study sets and groups definable in tame expansions of o-minimal structures. Let be an expansion of an o-minimal $\mathcal…

math.LO2015★ 2 cited

On definable Skolem functions in weakly o-minimal non-valuational structures

Pantelis E. Eleftheriou, Assaf Hasson, Gil Keren

We prove that all known examples of weakly o-minimal non-valuational structures have no definable Skolem functions. We show, however, that such structures eliminate imaginaries up…

math.LO2013

Coverings by open cells

Mário J. Edmundo, Pantelis Eleftheriou, Luca Prelli

We prove that in a semi-bounded o-minimal expansion of an ordered group every non-empty open definable set is a finite union of open cells.

math.LO2012★ 1 cited

Definable groups as homomorphic images of semilinear and field-definable groups

Pantelis Eleftheriou, Ya'acov Peterzil

We analyze definably compact groups in o-minimal expansions of ordered groups as a combination of semi-linear groups and groups definable in o-minimal expansions of real closed fie…

math.LO2011★ 3 cited

Interpretable groups are definable

Janak Ramakrishnan, Ya'acov Peterzil, Pantelis Eleftheriou

We prove that in an arbitrary o-minimal structure, every interpretable group is definably isomorphic to a definable one. We also prove that every definable group lives in a cartesi…

math.LO2011

Definable quotients of locally definable groups

Pantelis Eleftheriou, Ya'acov Peterzil

We study locally definable abelian groups $\CU$ in various settings and examine conditions under which the quotient of $\CU$ by a discrete subgroup might be definable. This turns o…