Dharaben Rameshbhai Thakkar Chosen as Recipient of the ACM India 2025 Doctoral Dissertation Award

January 16, 2026

Dharaben Rameshbhai Thakkar is the recipient of the ACM India Doctoral Dissertation Award 2025. Dharaben’s dissertation titled “On Computing Optimal Representations of Finite Groups” makes breakthrough contributions in computational group theory, including design of optimal data structures, minimal generating set computation, and complexity-theoretic insights into minimal permutation degree. Her dissertation has resolved long-standing open problems at the intersection of group theory, algorithms and complexity theory, and has led to interesting follow-up work that have gone on to answer additional open questions in the area. Dharaben’s dissertation work was done at the Indian Institute of Technology Gandhinagar under the supervision of Prof. Bireswar Das.

Dharaben’s dissertation makes multiple foundational contributions to the theory of computing with groups. Her work shows for the first time that the minimal generating set problem for finite groups is solvable in polynomial time, resolving a question that has remained open for close to 70 years. This result has important consequences for other algorithms as well that work on finite groups, and throws new light on the mathematical structure of the generating sets of finite groups. In another line of work, Dharaben shows that it is possible to design a data structure that can store a finite group of order n using only n words in memory, while allowing group multiplication to be done in constant time. This problem had remained open for close to 20 years, and Dharaben’s work effectively settles the question of efficient representation of finite groups. Her work also shows that the minimum faithful permutation representation of a subgroup of the symmetric group can be computed in randomized polynomial time, when the group belongs to an important class called semi-simple groups, i.e. has no Abelian normal subgroups. Prior to her work, not much was known about the worst-case complexity of this problem for any reasonably general class of groups.

Dharaben’s dissertation has re-kindled interest in problems that were long thought to be too hard to admit efficient solutions. The jury of the award was unanimous in its choice of Dharaben’s dissertation for the ACM India Doctoral Dissertation Award 2025.

The ACM India Doctoral Dissertation Award was established in 2011. This award recognizes the best doctoral dissertation in Computer Science and related disciplines from a degree-awarding institution based in India for each academic year, running from 1 July of one year to 30 June of the following year. The ACM India Doctoral Dissertation Award is accompanied by a prize of ₹2,00,000. An Honorable Mention award, given to nomination(s), if any, that missed the award by a narrow margin this year, is accompanied by a prize of ₹1,00,000, that is shared among the recipient(s).  The winning dissertation(s) will be published in the ACM Digital Library. Financial support for both the award and honorable mention is provided by Tata Consultancy Services (TCS). Please see the ACM India Doctoral Dissertation Award page for additional information on current and past recipients.

Please join us in congratulating Dharaben Rameshbhai Thakkar for her significant achievement.