=
Andre Nies' home page
Talks I have given at conferences, workshops, and in some cases seminars.
2025 Randomness via effective descriptive set theory . Limits of computability, definability, provability , IMS, Singapore. 2024 The trivial units property and the unique product property for torsion free groups . Joint meeting of the NZMS, AustMS and AMS, Auckland , special session on groups, actions and computations.
Randomness, dimension, and profinite groups . Joint meeting of the NZMS, AustMS and AMS, Auckland , special session on computability theory and applications. Describing a group by a first-order sentence . New methods in group actions on manifolds, Korea Institute of Advanced Study . Borel classes of closed subgroups of Sym(N) . Nankai Logic Colloquium, Nankai University . Two “almost sure” theorems under the lens of algorithmic randomness . Randomness, information and complexity , CIRM, Luminy. 2023 The Borel complexity of the bi-interpretability relation between omega-categorical structures . Generic structures , Banach Centre, Bedlewo. Representing
totally disconnected, locally compact groups by countable structures . Totally disconnected locally compact groups: local to global , Uni Muenster. Prime numbers, factorization, and algorithms . ISA- Institute of Advanced Studies, Bologna . Computably
totally disconnected, locally compact groups . Cross-Alps Logic Seminar , online. Undecidability and quantum information theory . Center for Quantum Technologies , NU Singapore. Martin-Loef randomness, 2-randomness, and reverse mathematics . From omega to Omega , Inst. Mathematical Sciences, Singapore. 2022 Computably totally disconnected locally compact groups . Computational Aspects
of Totally Disconnected Locally Compact Groups , University of Newcastle, Australia. Computability theory and quantum information theory . QuSoft, CWI, Amsterdam. 20 years of K-triviality . International conference on computability, complexity and randomness , Isaac Newton Institute, Cambridge, UK. Randomness for infinite sequences of quantum bits . New Directions in Computability Theory , CIRM, Marseille. Video . 2021
The search for FA presentable groups . Automata Theory and Applications: Games, Learning and Structures , IMS, Singapore. When can a totally disconnected locally compact group be called computable? . Workshop Totally Disconnected Locally Compact Groups via Group Actions (21w5151), Banff. Video . Computability for totally disconnected locally compact groups . Workshop Algorithmic Presentations in Mathematicss (APM-2021), Sochi, Russia.
Undecidability and algorithmic randomness for spin chains . Workshop on Logic, Quantum Computing, and Artificial Intelligence , Arak University, Iran, July (online). Duality between topological groups and approximation groupoids . Third Workshop on Digitalization and Computable Models (WDCM 2021), Sobolev Institute and Kazan Federal University, July (online). Joint work with Melnikov, and also Tent and Schlicht. Calibrating word problems of groups via the complexity of equivalence relations . Joint work with Sorbi. Workshop on Equivalences, Numberings, Reducibilities, Udine, June (online). Maximal towers and ultrafilter bases in computability theorys (video) . Midwest Computability together with Computability theory and applications online seminars, May. Slides 2020
Groups and first-order logic . International Congress on Mathematics and Applications (ICMA 2020), Mahidol University, Bangkok, Dec. Metric spaces and computability theory . Mal'cev meeting, Novoskibirsk, Nov (online). Discovering structure within the class of K-trivial sets (video) . CTA online seminar, August. Slides Randomness and initial segment complexity for probability measures . With Frank Stephan. STACS 2020, Montpellier. Journal paper. Expressivity of first-order logic for profinite groups . Covers research with Segal and Tent. CARMA seminar, University of Newcastle, Feb. 2019
Muchnik degrees and cardinal characteristics . With B. Monin. Set theory of the reals, Casa Matemática Oaxaca, August. The complexity of the isomorphism relation between oligomorphic groups . Joint work with Philipp Schlicht and Katrin Tent. Set theory of the reals, Casa Matemática Oaxaca. The remarkable expressivity of first-order logic for profinite groups . Joint work with Dan Segal and Katrin Tent. Conference on algebra and Mathematical Logic, Kazan, June. Effective metric Scott analysis . Institute of Mathematical Sciences, National University of Singapore, June. Quantum information science. Mathematical background. School of Computer Science, Auckland University, May. 2018
Topological isomorphism for classes of closed subgroups of Sym(N) . Descriptive set theory conference, Bernoulli Center, June. Seminar Talk Uni Bonn October about the same topic.
Closure of resource bounded randomness notions under polynomial time permutations . STACS 2018, Caen, France, February. Quantum Martin-Loef randomness and the Shannon-McMillan-Breiman Theorem . Algorithmic questions in dynamical systems, Toulouse, March. 2017
Randomness for infinite sequences of quantum bits . CCR 2017, Mysore, India, July 5. Sets that coincide with 1/2 − ε of each computable set . Leibniz Zentrum, Dagstuhl, Feb. 17. Structure within the class of K-trivial sets . NTU seminar, Feb. 6. My work with Rod 1995-2001 . Rodfest, Traumati Beach, January 5-8. 2016
Describing finite groups by first-order sentences of polylogarithmic length . Randomness and quantum computation . Lowness, Randomness, and Computable Analysis . Lightface Pi03-completeness of density sets under effective Wadge reducibility . With Gemma Carotenuto. Randomness connecting to set theory and to reverse mathematics . The complexity of isomorphism between profinite groups . 2015
Randomness and Analysis: a tutorial . Continuity, Computability, Constructivity (CCC), Sept 2015 , Kochel near Munich.
Part 1: Randomness notions and almost everywhere theorems
Part 2: Lebesgue density and its applications to anti-randomness
A unifying approach to the Gamma question . Local compactness for computable Polish metric spaces is Pi-1-1 complete . Objects of greatest complexity in their class . Multiple recurrence and algorithmic randomness . Interactions of computability and randomness . The Gamma question and cardinal characteristics . 2014
Compression and Randomness. Poster . Slides .
An analogy between cardinal characteristics and highness properties of oracles .
Differentiability of polynomial time computable functions .
Groups and first-order logic . 2013
The complexity of similarity relations for Polish metric spaces . How the Lebesgue density theorem resolved the covering problem . Metric spaces and computability theory .
Categoricity for compact computable metric spaces . With A. Melnikov.
Differentiability and porosity
Complexity of isomorphism relations 2012
Demuth randomness and its variants
"Almost everywhere'' theorems and algorithmic randomness
Ten years of triviality
Complexity of equivalence relations
Randomness interacts with computable and polynomial time analysis
Coding with first-order formulas
2011
Introductory talk
to the Conference Analysis and Randomness in Auckland 2011.
K-triviality in computable metric spaces
Borel Structures and Borel theories
Measuring the complexity of Delta-2 sets via their changes
Randomness and computable analysis: results and open questions
2010
Interactions of Computability and Randomness
Borel Structures
Random objects, and objects of low complexity
Randomness and differentiability (with J. Miller and V. Brattka).
2009
Three Lectures on applying randomness to computability. Assoc. Symb. Logic European Summer Meeting tutorial, Sofia. Slides
or Paper version.
Superhighness and strong jump traceability.
Future directions in Computability and Randomness.
Upper bounds for ideals in the Turing degrees.
Tutorial on cost functions.
Tutorial on randomness via effective descriptive set theory.
Cost functions and lowness properties.
2004-08
Weak reducibilities
Randomness, computability, effective descriptive set theory
Lowness properties and Highness properties
Randomness via computability theory and effective
descriptive set theory
NUS Singapore, June 2006
Recent results relating computability and randomness
SEALS, U of Florida, Mar 2006
Eliminating concepts: K-trivial equals low for K
IMS workshop, Singapore, July 2005
Algebras with finite descriptions
Assoc. Symb. Logic summer meeting, Athens, August 2005
Quasi-finitely axiomatizable groups
Univ. of Auckland and Univ. Paris, Jan 2005
FA-presentable structures: richness and limitations
WAssoc. Symb. Logic 2004, and Univ. Paris, Jan 2005
Randomness Notions and Lowness Properties
VIC2004, Wellington, New Zealand, Feb 2004
Randomness, K-triviality and Omega
UC Berkeley and UCLA, May 2004
1996-2003
Computable randomness and lowness.
Kolmogorov complexity and its applications. Dagstuhl, Germany, May 2003
Lowness properties
CL2002, Muenster, Germany
Model theoretic properties of
structures from computability theory , Oberwolfach, Jan 2001
How expressive is the first--order
language for groups? Math. Dept colloquium, U. of Chicago,
2001
Global properties of degree
structures Boulder computability workshop (AMS), 1999
Model theory of degree
structures, LMPS 99, Krakow, 1999
Definability and undecidability
PUC-Rio,
1999
Approximations to bi-interpretability
with N , XI. Latin American Logic Symposion, Merida, Venezuela, 1998
Homogeneity properties
of
free groups, Albany Group Theory Conference, 1997
Definability Lemmas Kazan
recursion theory meeting (WORCT 97), 1997
Undecidability of the exponential
time degrees and effective algebraAssoc. Symb. Logic meeting, 1997
(joint with Shore and Slaman) Coding
and definability in the r.e degrees
Oberwolfach, 1996
