I mainly used to work alone (except only one joint paper with my thesis supervisor) or only with my project students in the early years of my research career. However, lately I have started collaborating with various persons, and would like to extend my collaboration network, along with continuing my own independent projects. Following is the list (does not follow any specific order in any aspect) of my collaborators.

Following is a country wise partial list (not in any specific order) of persons (non-student) with whom I have been collaborating in last five years.

Collaborators

1. From Abroad
   
   
   1. USA
      
      
      1. Aneta Siemiginowska, Harvard-Smithsonian Center for Astrophysics, Harvard University.
      2. Paul Joseph Wiita, Princeton University and Georgia State University.
      3. Monika Moscibrodzka, University of Illinois at Urbana-Champaign.
      4. Daniel Proga, University of Nevada, Las Vegas.
      
      
   2. Europe
      
      
      1. Bozena Czerny, N. Copernicuis Astronomical Institute, Warsaw, Poland.
      2. Agatha Rozanska, N. Copernicuis Astronomical Institute, Warsaw, Poland.
      3. Edward Malec, Marian Smoluchowski Institute of Physics. Jagiellonian University, Cracow, Poland.
      4. Patryk Mach, Marian Smoluchowski Institute of Physics. Jagiellonian University, Cracow, Poland.
      5. Vladimir Karas, Relativistic Astrophysics Group, Astronomical Institute of the Academy of Sciences, Czech Republic.
      6. Mihaw Dovciak, Relativistic Astrophysics Group, Astronomical Institute of the Academy of Sciences, Czech Republic.
      7. Thomas Pechacek, Relativistic Astrophysics Group, Astronomical Institute of the Academy of Sciences, Czech Republic.
      8. Devaki Kunneriath, Relativistic Astrophysics Group, Astronomical Institute of the Academy of Sciences, Czech Republic.
      9. Neven Bilic, Rudjer Boskovic Institute, Croatia.
      10. Horje Abraham, Rudjer Boskovic Institute, Croatia.
      11. Wolfgang Kundt, Argelander-Institute fur Astronomie, University of Bonn, Germany, and Max-Planck Institute of Radio Astronomy, Germany.
      
      
   3. Asia
      
      
      1. Madonnlily Lei Huang, Shanghai Astronomical Observatory, China.
      2. Ahpishit Ungkitchanukit, Theoretical Jigh Energy Physics and Cosmology Group, Chulalongkorn University, Bangkok, Thialand.
      3. Pawel Lachowicz, Temasek Laboratory, Singapore.
      4. Young Chol Minh, Korea Astronomy and Space Scence Institute, Daejeon, Korea.
      5. Makoto Inoue,Academia Sinica Institute of Astronomy & Astrophysics Taiwan, and National Astronomical Observatory of Japan (NAOJ), Japan.
   
   
2. From India
   
   
   1. Jayanta K Bhattacharjee, S. N. Bose National Centre for Basic Sciences, Kolkata.
   2. A. R. Rao, Tata Institute of Fundamental Research, Mumbai, India.
   3. Vinod Krishan Indian Institute of Astrophysics & Raman Research Institute, Bangalore.
   4. Arnab K Ray, Jaypee University of Engineering & Technology, India.
   5. Sankhasubhra Nag, Sarojini Naidu Colege, Calcutta.
   6. Suparna Roychowdhury, St. Xavier's college, Calcutta, India.
   7. Sourav Bhattacharaya, Harish Chandra Research Institute, Allahabad.
   8. Archan S Majumdar, S. N. Bose National Centre for Basic Sciences, Kolkata.
   9. Sidhhartha Sinha S. N. Bose National Centre for Basic Sciences, Kolkata.
   10. Pratik Tarafdar S. N. Bose National Centre for Basic Sciences, Kolkata.

Following is the list (not in any specific order) of persons, who are not yet my direct collaborators, but extensive academic interactions with whom turned out to be quite useful in my research endeavoure:

1. Robert (Bob) V. Wagoner, Stanford University, USA.
2. William (Bill) G. Unruh, University of British Columbia, Vancouver, Canada.
3. Walter Thirring Erwin Schrodinger Institute, Vienna, Austria.
4. Theodore A. (Ted) Jacobson, University of Maryland, College Park, USA.
5. Marek A. Abramowicz, Physics Department Go¶teborg University Sweden.
6. Ronald Taam, Northwestern University, USA.
7. Nikola Shakura, Starnberg Astronomical Institute &ams; Moscow State University, Russia.
8. John Miller, Oxford University, UK, and SISSA, Italy.
9. Mitch Begelman University of Colorado, Boulder, USA.
10. Arnab Rai Choudhury Indian Institute of Science, Bangalore, India.
11. Mark. R. Morris, University of California Los Angeles, USA.
12. Robert (Bobby) Beig, University of Vienna and Erwin Schrodinger Institute, Vienna, Austria.