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Inder Bir Singh Passi

The first twelve articles of this issue are contributed by invitees of the programme “Group Algebras, Representations and Computation” held at ICTS Bangalore during October 14–23, 2019, a programme which also included sessions to honour the mathematical achievements of Prof. IBS Passi. Five out of twelve articles are extensive up-to-date surveys and the remaining seven are original research articles.

The journal records with appreciation the efforts of Professors Gurmeet K. Bakshi (Panjab University, Chandigarh), Pooja Singla (Indian Institute of Technology, Kanpur), and Manoj K. Yadav (Harish-Chandra Research Institute, Prayagraj (Allahabad)) who were asked to be the guest editors and handle all aspects of the editorial work for the papers received.

The journal is proud to present these articles here in honour of Prof. IBS Passi on his 80th birthday.

From Birthday celebrations to memories...

While this issue was about to come in the fall of 2021, the birthday greetings turned to memories. Prof IBS Passi (popularly known as Passi Saab in India), a stalwart academician, heaved his last breath on 2nd October 2021.

Inder Bir Singh Passi was born on 20 August 1939 in Bilaspur, Haryana (India). He obtained his doctoral degree from University of Exeter in 1966 and later moved to Kurukshetra University as a reader in Mathematics. In 1979 he joined Panjab University Chandigarh as full a professor and retired in 2000. He was a visiting professor at Harish Chandra Research Institute, Allahabad during 2000-2005. In 2005, Panjab University conferred upon him the title of emeritus professorship. Passi was awarded INSA senior scientist during 2005-09 and INSA honorary scientist during 2017–18. He had been honorary Professor at Indian Institute of Science Education and Research, Mohali since 2007 and laid the foundation of the mathematics department. He was an adjunct professor at Harish Chandra Research Institute, Allahabad during 2014–2016.

His career was decorated with various awards and honours: he was a fellow of all the three major science academies in India, viz. Indian National Science Academy (INSA), National Academy of Sciences, India (NASI), Indian Academy of Sciences, (IASc), he was the recipient of Shanti Swarup Bhatnagar prize for Science and Technology, the highest science award in India, in the mathematical sciences category, and the Prasanta Chandra Mahalanobis medal by Indian National Science Academy. He had been in the editorial boards of various national and international journals, including this journal.

Passi was a renowned algebraist, who made significant contribution to the theory of group-rings. His results on the dimension subgroups, augmentation powers in group rings, category theory, homological algebra and related problems have received wide recognition. Passi has been credited as cofounder of the so called HeLP method to compute constraints on partial augmentations of torsion units in integral group rings required for the validity of the Zassenhaus conjecture. He wrote several books and monographs which constitute a reference for undergraduate and graduate students as well as researchers.

Passi was a man of principles and a paragon of nobility. His mathematical eminence and charismatic personality has motivated several generations of aspiring mathematicians. He had been active in mathematics till the very end of his life. We are proud of his mathematics legacy.

Rahul Roy, Editor.