activity
20072026
most citedDefinable minimal collapse functions at arbitrary projective levels

20 citations · 140 across the 30 of their papers we have counts for

collaborators

32 papers

math.LO2026

Locally countable graphs of second projective class not generated by countably many projective functions

Vladimir Kanovei, Vassily Lyubetsky

To answer a question by Rettich and Serafin, we define a model of set theory in which there exists a locally countable graph on a subset of the real line, which is not…

math.LO2026

On Petr Novikov's problem of ordered systems of uniform sets

Vladimir Kanovei, Vassily Lyubetsky

We prove that every ordinal is the order type of a certain system of uniform Borel sets in the sense of a well-ordering relation defined by Petr Novikov. This result gives…

math.LO2025

Notes on the equiconsistency of ZFC without the Power Set axiom and second order PA

Vladimir Kanovei, Vassily Lyubetsky

We demonstrate that theories , , (minus means the absence of the Power Set axiom) and , (minus means the absenc…

math.LO2024

On the significance of parameters and the projective level in the Choice and Comprehension axioms

Vladimir Kanovei, Vassily Lyubetsky

We make use of generalized iterations of Jensen forcing to define a cardinal-preserving generic model of ZF for any and each of the following four Choice hypotheses: (1) $…

math.LO2022★ 1 cited

The parameterfree Comprehension does not imply the full Comprehension in the 2nd order Peano arithmetic

Vladimir Kanovei, Vassily Lyubetsky

The parameter-free part of , the 2nd order Peano arithmetic, is considered. We make use of a product/iterated Sacks forcing to define an -model o…

math.LO2022★ 7 cited

A model in which the Separation principle holds for a given effective projective Sigma-class

Vladimir Kanovei, Vassily Lyubetsky

In this paper, we prove the following: If , there is a generic extension of -- the constructible universe -- in which it is true that the Separation principle holds for…