Lukas Fleischer

My name is Lukas Fleischer. I was born on March 6th, 1990 near Stuttgart and I am currently living in Waterloo, ON.

From August 2015 to April 2019, I was a research assistant in the Institute for Formal Methods in Computer Science at the University of Stuttgart. From May 2019 to December 2019, I was a postdoctoral researcher in the Cheriton School of Computer Science at the University of Waterloo, working with Jeffrey Shallit. My primary research areas are automata theory, formal languages, semigroup theory, algorithms, computational complexity and formal verification. A list of my publications can be found here and on DBLP.

I actively contribute to several open source projects. Please scroll down for a (not necessarily complete) list.

Conference Articles

1. Lukas Fleischer and Manfred Kufleitner. Testing Simon's congruence. MFCS 2018.   
2. Lukas Fleischer. The Intersection Problem for Finite Semigroups. DLT 2018.   
3. Lukas Fleischer. On the Complexity of the Cayley Semigroup Membership Problem. CCC 2018.   
4. Lukas Fleischer and Manfred Kufleitner. The Intersection Problem for Finite Monoids. STACS 2018.   
5. Volker Diekert and Lukas Fleischer. Church-Rosser Systems, Codes with Bounded Synchronization Delay and Local Rees Extensions. WORDS 2017.   
6. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Finite Transformation Semigroups. CSR 2017.   
7. Lukas Fleischer and Manfred Kufleitner. Operations on Weakly Recognizing Morphisms. DCFS 2016.   
8. Lukas Fleischer and Manfred Kufleitner. Efficient Algorithms for Morphisms over Omega-Regular Languages. FSTTCS 2015.   
9. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. Block Products and Nesting Negations in FO². CSR 2014.   

Journal Articles

1. Lukas Fleischer and Trevor Jack. The Complexity of Properties of Transformation Semigroups. International Journal of Algebra and Computation. World Scientific, 2019.   
2. Lukas Fleischer and Manfred Kufleitner. The Complexity of Operations on Weakly Recognizing Morphisms. RAIRO-Theor. Inf. Appl., volume 53, number 1-2, pp 1–17. EDP Sciences, 2018.  
3. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Deterministic Finite Automata. Theory of Computing Systems, volume 63, issue 4, pp 666–687. Springer, 2018.  
4. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. The Half-Levels of the FO² Alternation Hierarchy. Theory of Computing Systems, volume 61, issue 2, pp 352–370. Springer, 2017.  

Unpublished Papers

1. Lukas Fleischer and Jeffrey Shallit. The State Complexity of Lexicographically Smallest Words and Computing Successors. Technical report, 2019.
2. Lukas Fleischer, Samin Riasat, and Jeffrey Shallit. New Bounds on Antipowers in Binary Words. Technical report, 2019.  
3. Lukas Fleischer and Jeffrey Shallit. Words With Few Palindromes, Revisited. Technical report, 2019.  
4. Lukas Fleischer and Jeffrey Shallit. Words Avoiding Reversed Factors, Revisited. Technical report, 2019.  
5. Lukas Fleischer. Algorithms and Complexity Results for Finite Semigroups. PhD thesis, 2019.  
6. Lukas Fleischer. Efficient Membership Testing for Pseudovarieties of Finite Semigroups. Technical report, 2018.