Schur Multiplier and Representation Theory (2025)

Convener(s)

 
Name:  Prof. Manoj Kumar Dr. Sunil Kumar Prajapati                    
Mailing Address: HRI Prayagraj IIT Bhubaneswar
Email: myadav at hri.res.in  skprajapati at iitbbs.ac.in

Abstract: It is well established that cohomology theory and representation theory of groups  have profound connections. Such connections also exist for category theory, Lie algebras and more.  In the proposed AIS, we have a plan to train students with basic cohomology and representation theory of groups so that they can explore these connections in group theory settings. Starting with the basics of the second cohomology group of a finite group; the restriction, inflation, and transgression homomorphisms will be studied, and the Hochschild-Serre exact sequence for cohomology of groups will be established. We then specialise to the  Schur multiplier M(G) of a finite group G, which is defined to be the second cohomology group of G with coefficients in C^{*}, the group of non-zero complex numbers. The Schur multiplier plays an important role in the theory of extensions of groups and the study of Projective representations of finite groups. Schur Multiplier is also used as a powerful tool in other areas such as algebraic number theory, block theory of group algebras, and classification of finite simple groups etc. On the other hand, representation theory, as is well known, is one of the very fundamental objects in mathematics.  Having its origins in algebra and number theory,  representation theory of groups has applications in diverse areas such as physics, statistics, and engineering, to name a few. This workshop will focus on the second cohomology of groups,  Schur multiplier, and (projective) representation theory of finite groups. Assuming that participants are familiar with groups, rings, and modules, in the first week, we will develop the basic character theory of representations in characteristic zero along with the concept of cohomology of finite groups. In the second week, we will discuss the projective representations of finite groups and the Schur Multiplier of finite groups in detail.  Representations of GL_2(F_q) will be discussed in adequate detail.

Dates: 

Thursday, December 4, 2025 - 09:00 to Tuesday, December 16, 2025 - 21:00

Venue: 

Venue Address: 

 

Harish-Chandra Research Institute, Prayagraj

 

 

Venue State: 

Venue City: 

PIN: 

211019

Syllabus: 

Detailed syllabus

Speaker

No. of Lectures (90 min.)

Detailed Syllabus

Sunil K Prajapati (IIT Bhubaneswar)

2

Group Representation (GR): Group representations and characters, Maschke’s Theorem and Complete Reducibility, Orthogonality Relations

Amit Kulshrestha (IISER Mohali)

2

Irreducibility Criteria (IC): Frobenius reciprocity theorem, conjugate representation, Mackey Irreducibility criteria, Wigner-Mackey Method of Little Group

Shripad Garge (IIT Bombay)

6

Group Cohomology (GC): Cohomology Groups, Second cohomology group, and central extensions, The homomorphism restriction, inflation and transgression, Hochschild-Serre exact sequence

Sumana Hatui (NISER Bhubaneswar)

4

Projective Representation (PR): Projective representation, twisted group algebra, representation groups (existence and characterization)

Pradeep Rai (Mahindra University, Hyderabad)

6

Schur Multiplier (SM): Basic results, Schur Multiplier of abelian groups, Schur’s formula, covering groups, exponent and central quotient, some results on p-groups

Anupam Kumar Singh (IISER Pune)

4

General linear group over F_q (GLG): Representations of GL_2(F_q)

References:

  1. M. Isaacs, Character Theory of Finite Groups
  2.  C. W. Curtis, Pioneers of Representation Theory
  3. J. Alperin and R. Bell, Groups and Representations
  4. G. Karpilovsky, Projective Representations of Finite Groups
  5. G. Karpilovsky, The Schur Multiplier
  6. J.-P. Serre, Linear Representations of Finite Groups
  7. W. Fulton and J. Harris, Representation Theory
  8. D.J. Benson, Representations and Cohomology, Volumes I and II

Tutor's Name with affiliation:

  1. Ram Karan Choudhary, IIT Bhubaneswar
  2. Saikat Panja, ISI Bangalore
  3. Vipul Kakkar, Central University of Rajasthan, Ajmer
  4. Harish Krishnani, IISER Mohali 

 

Time Table: 

 

 

Day

Date (Dec 2025)

Lecture 1

(9:30-11)

Tea (11:05-11:25)

Lecture 2 (11:30-1:00)

Lunch (1:05-2:25)

Tutorial Session (TS) (2:30-3:30)

Tea (3:35-3:55)

Tutorial Session (TS) (4:00-5:00)

Snacks (5:05-5:30)

Thur

04

SKP

 

SG

 

TS- GC

 

TS- GC

 

Fri

05

SKP

SG

TS- GR

TS- GR

Sat

06

AK

SG

TS- GC

TS- GC

Sun

07

AK

SG

TS- IC

TS- IC

Mon

08

SH

SG

TS- GC

TS- GC

Tues

09

SH

SG

TS- PR

TS- PR

WEDNESDAY-OFF

Thur

11

PKR

 

SH

 

TS- PR

 

TS- PR

 

Fri

12

PKR

SH

TS- SM

TS- SM

Sat

13

PKR

AKS

TS- PR

TS- GLG

Sun

14

PKR

AKS

TS- SM

TS- SM

Mon

15

PKR

AKS

TS- GLG

TS- GLG

Tues

16

PKR

AKS

TS- SM

TS- SM

 

Full forms for the abbreviations of speakers:

     SKP: Sunil Kumar Prajapati (IIT Bhubaneswar)

    AK: Amit Kulshrestha(IISER Mohali)

    SG: Shripad Garge (IIT Bombay)

    SH: Sumna Hatui (NISER Bhubaneswar)

    PKR: Pradeep Kumar Rai (Mahindra University)

    AKS: Anupam Kumar Singh (IISER Pune)

Full forms for the abbreviations related to the Tutorial session and Tutors' Name:

  1. TS- GR and TS- IC:Tutorial session on Group Representation (GR) and Irreducibility Criteria (IC)- Ram Karan Choudhary (IIT Bhubaneswar)

  2. TS- GC and TS- GLG: Tutorial session on Group Cohomology (GC) and General linear group over F_q (GLG)- Saikat Panja (ISI Bangalore)

  3. TS- PR: Tutorial session on Projective Representation (PR)- Harish Krishnani (IISER Mohali)

  4. TS- SM: Tutorial session on Schur Multiplier (SM)- Vipul Kakkar (Central University of Rajasthan, Ajmer)

Selected Applicants: 

List of Outstation Participants-AIS on Schur Multiplier and Representation Theory- 2025, HRI

Sl. No. SID Name Gender Affiliation Position in College/ University University/ Institute M.Sc./M.A. Year of Passing M.Sc./ M.A Ph.D. Degree Date
1 66645 Dr. Shushma Rani Female IISc Postdoc Punjabi University Patiala   14/06/2023
2 66652 Mr. Sutirtha Datta Male Indian Institute of Science Education and Research, Pune PhD student Indian Institute of Science Education and Research, Pune 2024  
3 66654 Ms. Antara Manik Female Indian Institute of Science Education and Research PhD Indian Institute of Technology, Madras 2023  
4 66655 Mr. Amal V Male IIT BHUBANESWAR PhD CENTRAL UNIVERSITY OF KERALA 2021  
5 66657 Mr. Bhupinder Singh Saddal Male IIT Bhubaneswar PhD Ranchi University, Ranchi 2021  
6 66659 Mr Subham Das Male IIT Bhubaneswar PhD NIT Durgapur 2023  
7 66661 Mr. Shayon Bhadra Male BITS-Pilani Hyderabad campus PhD Student Tezpur University 2019  
8 66665 Mr. Velmurugan Subramani Male The Institute of Mathematical Sciences, Chennai PhD University of Madras 2021  
9 66683 Ms. Sonakshee Arora Female Indian Institute of Technology, Jammu PhD NIT Jalandhar, Punjab 2020  
10 66732 Mr. Rishabh Jain Male Indian Institute of Science Education and Research (IISER) Pune PhD Indian Institute of Technology (IIT) Kanpur/ M.Sc. 2023  
11 66735 Ms Simran Saukath Azim Female National Institute of Science Education and Research (NISER) 3rd year Int-Phd student National Institute of Science Education and Research, Bhubaneswar, Odisha Appeared / Awaiting Result  
12 66743 Dr. Pushpendra Singh Male Indian Institute of Technology Jodhpur Research Fellow Indian Institute of Technology Jodhpur 2020 10/10/2025
13 66765 Mr. Arijit Mahato Male National Institute of Science Education and Research PhD NISER, Bhubaneswar 2025  
14 66774 Mr. Heman Farishta Male The LNM Institute of Information Technology PhD The LNM Institute of Information Technology 2022  
15 66797 Mr. Gaurav Kumar Male IIT Jodhpur PhD MSBU Bharatpur 2022  
16 66819 Mr. Sharang Thimmaiah Male School of Interwoven Arts and Sciences, Krea University PhD Student St. Joseph's College (Autonomous), Bengaluru/ Bengaluru City University 2023  
17 66832 Mr. Umesh Shankar Male Indian Institute of Technology, Bombay PhD IISER Trivandrum 2019  
18 66850 Ms. Seema Rani Female IIT Roorkee Phd Guru Jambheshwar University Hisar 2020  
19 66893 Ms Sahanawaj Sabnam Female Niser Bhubaneswar PhD Jadavpur University 2019  
20 66904 Ms. Ila Ahmad Female Indian Institute of Science Education and Research, Bhopal. Integrated PhD, third year student Indian Institute of Science Education and Research, Bhopal. Appeared / Awaiting Result  
21 66915 Dr. Rahul Kaushik Male NISER Bhubaneswar Postdoctoral Fellow   2015 24/06/2022
22 66937 Ms Papi Ray Female IISER Mohali Postdoc Calcutta University 2015 11/11/2022
23 66949 Ms. Poonam Nayak Female National Institute of Science Education and Research PhD Indian Institute of Technology Bombay 2023  
24 66953 Ms Vigneshini Bharathi Female KREA University PhD student Ramanujan Institute for Advanced Study in Mathematics 2019  
25 66983 Mr. Sanjay Mukherjee Male NISER, Bhubaneswar PhD Ramakrishna Mission Vivekananda Educational and Research Institute, Belur math 2019  
26 67000 Ms. Archita Gupta Female Indian Institute of technology, Kanpur PhD student Indian Institute of Technology, kharagpur 2020  
27 67006 Dr. Ankita Parashar Female Indian Institute of Technology Delhi Ph.D. University of Delhi 2019 02/08/2025
28 67043 Mr Nishant Rathee Male ISI Delhi Postdoc IIT Madras 2016 01/03/2023
29 66718 Mr Abdul Mateen Naikoo Male Nit Srinagar Phd   2023  
30 67100 Mr. Tinu Dhali Male IIT Kanpur 5 th year PhD student ISI, Bangalore 2021  
List of Local Participants-AIS on Schur Multiplier and Representation Theory- 2025, HRI
Sl. No. SID Name Gender Affiliation Position in College/ University University/ Institute M.Sc./M.A. Year of Passing M.Sc./ M.A Ph.D. Degree Date
1 66767 Mr. Arpan Kanrar Male Harish-Chandra Research Institute PhD IIT (ISM) Dhanbad 2020  
2 66779 Mr. Rithwik M R Male Harish-Chandra Research Institute PhD Pondicherry University 2022  
3 66785 Mr. Himanshu Kesarwani Male Motilal Nehru National Institute of Technology Allahabad Research Scholar (PhD pursuing) M.Sc., University of Allahabad 2018  
4 66815 Ms. Subiksha Kannan Female Harish Chandra Research Institute PhD student Indian Institute of technology Madras 2023  
5 66818 Ms Aparna Tripathi Female Harish-Chandra Research Institute PhD University of Delhi 2018  
6 66892 Ms. Nevetha P R Female Harish-Chandra Research Institute PhD Student   2024  
7 66919 Mr Swapnil Sanap Male Harish-Chandra Research Institute PhD Student Savitribai Phule Pune University 2017  
8 66924 Mr. Susanta Mondal Male Harish-Chandra Research Institute PhD University of calcutta 2020  
9 66931 Mr. Neeraj Kumar Maurya Male Indian Institute of Information Technology Allahabad PhD Indian Institute of Technology Kharagpur 2022  
10 66938 Mr. Deepak Pal Male Indian Institute of Information Technology, Allahabad PhD UNIVERSITY OF ALLAHABAD 2018  
11 67040 Mrs. Suman Rani Female Harish Chandra Research Institute PhD Student Chaudhary Devi Lal University 2020  
12 67048 Mr Sudip Karmakar Male Harich-Chandra Research Institute Student(Ph.D) IIT Kanpur 2024  
13 67096 Mr. Pradeep Bisht Male Harich-Chandra Research Institute PhD Delhi University 2019  
Waiting List -AIS on Schur Multiplier and Representation Theory- 2025, HRI
Sl. No. SID Name Gender Affiliation Position in College/ University University/ Institute M.Sc./M.A. Year of Passing M.Sc./ M.A Ph.D. Degree Date
1 66773 Mr Abu Talib Male Indian Institute of Technology Roorkee PhD University of Hyderabad 2023  
2 66907 Ms. Sakshi Gupta Female IIT Jammu PhD Mnit, Jaipur 2023  
3 66744 Dr. Ashutosh Pandey Male Indian Institute of Technology Bhubaneswar Postdoc IISER Bhopal 2017 20/12/2023
4 66851 Ms. Anu Rani Jindal Female IIT Roorkee PhD Panjab University 2023  
5 66849 Mr. Theophilus Gera Male Sardar Vallabhbhai National Institute of Technology PhD Sardar Vallabhbhai National Institute of Technology 2024  
6 67041 Ms Abiya R Female Indian Institute of Science Education and Research (IISER) Berhampur. PhD student IISER Tirupati, BSMS (Physics, Mathematics) 2020  
7 66852 Ms. Varsha V Female Indian Institute of Science Education and Research, Bhopal Integrated PhD student Indian Institute of Science Education and Research, Bhopal Appeared / Awaiting Result  
8 66840 Mr Prashun Kumar Male Dr B. R. Ambedkar University Delhi PhD student Delhi University 2019  
9 66643 Mr. Amit Kumar Male UPES Asst. Prof. University of Allahabad 2019  
10 66650 Mr. Yerrapati Venkata Subbaiah Male Sardar Vallabhbhai National Institute of Technology PhD Student Sardar Vallabhbhai National Institute of Technology    

 

 

 

How to Reach: 

TBA

School Short Name: 

smrt

Last Date Application: 

Monday, March 31, 2025

School Type: 

AIS

Separate faculty form: 

0