Dr. Itamar Stein

Dr. Itamar Stein

 I am a lecturer at the mathematics unit of SCE

My main research interest is the representation theory of semigroups and categories

I try to find a combinatorial description of fundamental invariants of category algebras - mainly homological invariants

Another research interest is ordinary group representation theory. I am interested in combinatorial interpretation of branching rules for finite groups

I have also studied string rewriting systems, a topic in theoretical computer science

I have earned my Ph.D. in mathematics at Bar-Ilan university. My advisor was Prof. Stuart Margolis


Mathematics department


Decibel / 2015


2013-2017  Ph.D.  in Mathematics.  Bar-Ilan University, Israel. Dissertation title: Quivers and global dimension of monoid algebras.  Adviser: Prof. Margolis, S.     

2009-2012  M.Sc. (Summa cum Laude) in Mathematics. Bar-Ilan University, Israel.  Dissertation title: Graded monoids and graded monoid presentations.  Adviser: Prof. Margolis S.      

2004-2007  B.Sc. (Summa cum Laude) in Mathematics. Bar-Ilan University, Israel.      


Representation theory: Algebras of groups, semigroups and categories. Combinatorial and homological properties.

Semigroup theory: Ehresmann semigroups and their corresponding categories.

Algebraic combinatorics: Representation theory of finite groups. Branching rules.

Theoretical computer science: String rewriting systems. Decision problems and algorithms


Linear algebra

Discrete mathematics




1.     (with Adinayev, Arthur) Diamond Subgraphs in the Reduction Graph of a One-Rule String Rewriting System. Fundamenta Informaticae 178.3 (2021): 173-185

2.     Representation theory of order-related monoids of partial functions as locally    trivial category algebras.  Algebr. Represent. Theory 23 (2020), no. 4, 1543--1567. 

3.     The global dimension of the algebra of the monoid of all partial functions on an n-    set as the algebra of the EI-category of epimorphisms between subsets. J. Pure Appl. Algebra 223 (2019), no. 8, 3515-3536.

4.      Algebras of Ehresmann semigroups and categories. Semigroup Forum 95 (2017), no. 3, 509-526.

5.      The Littlewood-Richardson rule for wreath products with symmetric groups and the quiver of the category F≀FIn. Communications in Algebra 45.5 (2017): 2105-2126.

6.      The representation theory of the monoid of all partial functions on a set and related monoids as EI-category algebras. Journal of Algebra 450 (2016): 549-569.

7.      Reducing the gradedness problem of string rewriting systems to a termination problem. RAIRO-Theoretical Informatics and Applications 49.3 (2015): 233-254.