activity
20092020
most citedForking independence from the categorical point of view

21 citations · 76 across the 13 of their papers we have counts for

collaborators

19 papers

math.LO2020

Induced and higher-dimensional stable independence

Michael Lieberman, Jiri Rosicky, Sebastien Vasey

We provide several crucial technical extensions of the theory of stable independence notions in accessible categories. In particular, we describe circumstances under which a stable…

math.CT2020

Cofibrant generation of pure monomorphisms

Michael Lieberman, Leonid Positselski, Jiri Rosicky +1

We show that pure monomorphisms are cofibrantly generated---generated from a set of morphisms by pushouts, transfinite composition, and retracts---in any locally finitely presentab…

math.CT2019★ 2 cited

Hilbert spaces and -algebras are not finitely concrete

Michael Lieberman, Jiří Rosický, Sebastien Vasey

We show that no faithful functor from the category of Hilbert spaces with linear isometries into the category of sets preserves directed colimits. Thus Hilbert spaces cannot form a…

math.CT2019

Cellular categories and stable independence

Michael Lieberman, Jiří Rosický, Sebastien Vasey

We exhibit a bridge between the theory of cellular categories, used in algebraic topology and homological algebra, and the model-theoretic notion of stable independence. Roughly sp…

math.LO2019

Tameness, powerful images, and large cardinals

Will Boney, Michael Lieberman

We provide comprehensive, level-by-level characterizations of large cardinals, in the range from weakly compact to strongly compact, by closure properties of powerful images of acc…

math.LO2019

Sizes and filtrations in accessible categories

Michael Lieberman, Jiří Rosický, Sebastien Vasey

Accessible categories admit a purely category-theoretic replacement for cardinality: the internal size. Generalizing results and methods from arXiv:1708.06782, we examine set-theor…

math.LO2018

Tameness in generalized metric structures

Michael Lieberman, Jiri Rosicky, Pedro Zambrano

We broaden the framework of metric abstract elementary classes (mAECs) in several essential ways, chiefly by allowing the metric to take values in a well-behaved quantale. As a pro…

math.LO2018

A category-theoretic characterization of almost measurable cardinals

Michael Lieberman

Through careful analysis of an argument of Brooke-Taylor and Rosicky, we show that the powerful image of any accessible functor is closed under colimits of -chains, a suffic…

math.LO2018★ 21 cited

Forking independence from the categorical point of view

Michael Lieberman, Jiří Rosický, Sebastien Vasey

Forking is a central notion of model theory, generalizing linear independence in vector spaces and algebraic independence in fields. We develop the theory of forking in abstract, c…

math.LO2017★ 8 cited

Internal sizes in -abstract elementary classes

Michael Lieberman, Jiří Rosický, Sebastien Vasey

Working in the context of -abstract elementary classes (-AECs) - or, equivalently, accessible categories with all morphisms monomorphisms - we examine the two natural notions…

math.LO2017★ 10 cited

Universal abstract elementary classes and locally multipresentable categories

Michael Lieberman, Jiří Rosický, Sebastien Vasey

We exhibit an equivalence between the model-theoretic framework of universal classes and the category-theoretic framework of locally multipresentable categories. We similarly give…

math.LO2016★ 4 cited

Hanf numbers via accessible images

Michael Lieberman, Jiri Rosicky

We present several new model-theoretic applications of the fact that, under the assumption that there exists a proper class of almost strongly compact cardinals, the powerful image…

math.LO2015★ 19 cited

-Abstract Elementary Classes and other generalizations

Will Boney, Rami Grossberg, Michael Lieberman +2

We introduce -Abstract Elementary Classes (-AECs) as a broad framework for model theory that includes complete boolean algebras and Dirichlet series, and begin to develop the…

math.LO2015

Approximations of superstability in concrete accessible categories

Michael Lieberman, Jiri Rosicky

We generalize the constructions and results of Chapter 10 in Baldwin's "Categoricity" to coherent accessible categories with concrete directed colimits and concrete monomorphisms.…

math.LO2015★ 1 cited

Limits of abstract elementary classes

M. Lieberman, J. Rosický

We show that the category of abstract elementary classes (AECs) and concrete functors is closed under constructions of "limit type," which generalizes the approach of Mariano, Zamb…

math.LO2015

Metric abstract elementary classes as accessible categories

Michael Lieberman, Jiri Rosicky

We show that metric abstract elementary classes (mAECs) are, in the sense of [LR] (i.e. arXiv:1404.2528), coherent accessible categories with directed colimits, with concrete $\ale…

math.LO2014

Classification theory for accessible categories

Michael Lieberman, Jirí Rosický

We show that a number of results on abstract elementary classes (AECs) hold in accessible categories with concrete directed colimits. In particular, we prove a generalization of a…

math.LO2010★ 9 cited

Rank functions and partial stability spectra for tame AECs

Michael Lieberman

We introduce a family of rank functions and related notions of total transcendence for Galois types in abstract elementary classes. We focus, in particular, on abstract elementary…

math.LO2009★ 2 cited

A Topology for Galois Types in AECs

Michael Lieberman

We present a way of topologizing sets of Galois types over structures in abstract elementary classes with amalgamation. In the elementary case, the topologies thus produced refine…