Home Page of Tejinder Pal Singh

Affiliation | Research | CV | Publications | Students | Awards | Teaching | Popular Science | Schooling

Department of Astronomy and Astrophysics
Tata Institute of Fundamental Research
Homi Bhabha Road
Mumbai 400005
Designation : Professor
Email : tpsingh at tifr.res.in OR tejinder.tifr at gmail.com
Address from January 1, 2023 : Inter-University Centre for Astronomy and Astrophysics, Pune, India
The AIKYON Academy of Young Researchers in Foundational Physics
Tel: +91-22-22782600 (Office): +91-22-22783160 (Residence)
Research Interests :
Quantum Gravity; Unification and division algebras; Quantum Measurement Problem and Foundations of Quantum Mechanics; Gravitation Theories with Torsion; Cosmology - The Origin of Cosmic Acceleration and Dark Energy, The Cosmological Constant Problem and the Large Scale Structure of the Universe; Gravitational Collapse and Cosmic Censorship.

January 7, 2021 : Where does the fine structure constant come from? A theoretical derivation of the fine structure constant, from trace dynamics and the algebra of the octonions, yields the number 1/137.04006 Why do elementary particles have such strange mass-ratios? Preprint here

July 29, 2021 Why do elementary particles have such strange looking mass ratios? Blogpost
Mass Ratios
COLLOQUIUM AT TIFR: Towards the unification of the four fundamental forces, February 10, 2021 at 1600 hrs IST Link Here YouTube Recording
COLLOQUIUM AT TIFR: Why do elementary particles have such strange looking mass ratios? , February 9, 2022 at 1600 hrs IST Slides here YouTube Recording

A violation of the Tsirelson bound in the pre-quantum theory of trace dynamics
An E8 x E8 unification of the standard model with pre-gravitation, on an octonion-valued twistor space Talk at Paris Conference, June, 2022
Why do elementary particles have such strange mass ratios? - The importance of quantum gravity at low energies -
Forthcoming invited talk: Gravitation, and quantum theory, as emergent phenomena DICE 2022. Castiglioncello, Italy, September, 2022
Invited Review: Quantum theory without classical time: a route to quantum gravity and unification Talk at University of Regensburg, January 21, 2022
Majorana neutrinos, Exceptional Jordan algebra, and mass ratios for charged fermions
Left-Right symmetric fermions and sterile neutrinos from complex split biquaternions and bioctonions
Quantum theory without classical time: octonions, and a theoretical derivation of the fine structure constant 1/137, Talk at Perimeter Institute conference on `Octonions and the standard miodel'
Quantum gravity effects in the infra-red: a theoretical derivation of the low energy fine structure constant and mass ratios of elementary particles [Preprint at Researchgate], Delhi University Talk
Aikyons, Octonions, and Unification, BITS Pilani, Hyderabad Campus Talk, IIT Delhi Talk
Trace dynamics and division algebras: towards quantum gravity and unification,     Audio slides of Webinar at: Albert Einstein Institute, Potsdam, Monday September 21, 2020,     Aikyon Theory Simplified
Trace dynamics, and a ground state in spontaneous quantum gravity
Octonions, trace dynamics and non-commutative geometry: a case for unification in spontaneous quantum gravity
A basic definition for spin in the new matrix dynamics
Why does the Kerr-Newman black hole have the same gyromagnetic ratio as the electron? INO Lecture
The pollen and the electron: a study in randomness
Nature does not play dice on the Planck scale
Spontaneous Quantum Gravity, Video Lecture
Blog: Schrdinger's cat and Einstein's space-time in the twenty-first century
Dark energy as a large scale quantum gravitational phenomenon
Proposal for a new quantum theory of gravity V: A testable prediction
From quantum foundations to quantum gravity: an overview of the new theory
Proposal for a new quantum theory of gravity IV: Black Hole Entropy
Proposal for a new quantum theory of gravity III: Equations of quantum gravity
Proposal for a new quantum theory of gravity II : spectral action and trace dynamics
Quantum gravity as an emergent phenomenon
Proposal for a new quantum theory of gravity, ASET Colloquium, An elementary account, Plausibility arguments, BITS Goa Talk
Thinking about Quantum Gravity: YouTube Video Lecture Series Video#1 Playlist
Outline for a quantum theory of gravity
Space-time from collapse of the wave-function: Article, Blog Post
Testing the Limits of Quantum Mechanics Article, TIFR Colloquium
Space and time as a consequence of GRW quantum jumps
Testing spontaneous collapse through bulk heating experiments
Quantum theory and the structure of space-time

I am currently working on the deep theoretical connection between quantum foundations, and the sought for quantum theory of gravity. And I collaborate with experimentalists to test these ideas in the laboratory, and in the cosmological setting, as also in the context of black hole physics. Quantum theory, despite being extremely successful and agreeing with every experiment to date, poses difficult unresolved conceptual issues: the nature of the quantum-to-classical transition, the absence of position superpositions in the macroscopic world, quantum non-locality, and the problem of time in quantum theory. I have argued that addressing these issues points us towards the sought for quantum theory of gravity. Some of these issues have been addressed by spontaneous collapse theories, which provide a unified description of classical and quantum dynamics, by suggesting that the principle of quantum linear superposition is approximate, not exact. These theories are falsifiable, and are currently being tested in the laboratory. We have shown that the resolution of the problem of time in quantum theory guides us towards quantum gravity, and spontaneous localisation plays an important role in bridging the quantum gravitational world and the classical one. We have predicted the intriguing phenomenon of quantum interference in time, and spontaneous collapse in time - these are in principle testable in the laboratory, and constitute a test of quantum gravity. These ideas also seem to have important implications for black hole physics and cosmology, which are currently being investigated. You can get more information on these works from the articles listed above, and from my ongoing YouTube video lecture series `Thinking about Quantum Gravity’.
CV: Detailed CV
Date of Birth : 23rd July, 1962
Masters in Physics [Five Year Integrated Programme] : IIT, Delhi (1979-1984)
Ph. D. in Physics : TIFR, Mumbai (1984-1989)
Post-Doctoral Fellow at ICTP, Trieste : 1989-90
Faculty Member at TIFR since 1989
List of Publications :
PDF file
Link to Spires Database
Link to Google Scholar
Graduate Student(s):
Past Graduate Students :
Srimanta Banerjee
Sayantani Bera (post-doc, IUCAA, Pune)
Shreya Banerjee (post-doc, Ben Gurion University, Israel)
Priti Mishra [Faculty, Patna University]
Kinjalk Lochan [Faculty, IISER Mohali]
Aseem Paranjape [The Jurgen Ehlers Thesis Prize 2013 from International Society of General Relativity and Gravitation; Faculty, IUCAA, Pune]
Rakesh Tibrewala [Faculty, LNMIIT, Jaipur ]
Sashideep Gutti [Faculty, BITS Hyderabad]
Sukratu Barve [Faculty, Univ. of Pune]
Awards and Recognition :

CBSE HSC Examination (1977) : All-India Rank 11
CBSE Senior Secondary Examination [1979] : All-India Rank 3
IIT Delhi Silver Medal [1984]

Gravity Research Foundation [USA] Essay Contest :
3rd Prize (1998)
4th Prize (2004) [jointly with Cenalo Vaz, Cincinnati]
2nd Prize (2008)

Center for Excellence Visiting Scholar, Yukawa Institute for Theoretical Physics, Kyoto [Aug.-Oct. 2000]

Fourth Prize in 2009 Essay Contest of the Foundational Questions Institute (USA)
4th Prize in FQXi essay contest 2011
4th Prize in FQXi essay contest 2012, jointly with Angelo Bassi and Hendrik Ulbricht
2nd Prize in FQXi essay contest 2013, jointly with Angelo Bassi and Saikat Ghosh
3rd Prize in FQXi eessay contest 2014
Creative Thinking Prize in FQXi essay contest 2015, jointly with Anshu Gupta Mujumdar
4th Prize in FQXi essay contest 2018

John Templeton Foundation project grant for research on `Quantum physics and the nature of reality' [2011-2013]

Co-investigator: John Templeton Foundation project grant for research on 'Experimental and theoretical exploration of fundamental limits of quantum mechanics' PI: Hendrik Ulbricht (Southampton), Co-investigator: Angelo Bassi (Trieste) 2013-2016

Member, Foundational Questions Institute, USA
Teaching [Graduate Courses at TIFR]:
Classical Electrodynamics [1993]
Astronomy and Astrophysics [1995]
Classical Electrodynamics [1998]
Statistical Mechanics [2001]
Classical Mechanics [2003]
Statistical Mechanics [2009]
General Relativity and Cosmology [2013]
Some Popular Science Articles / Podcast / Youtube Video:
Special Relativity for the School-Going Child
Quantum theory and the Cosmological Constant
Quantum theory, gravity, and the standard model of particle physics
FQXi Lecture 'Quantum measurement and quantum gravity'
FQXI Podcast: Testing the quantum limits
YouTube Video: Does Nature Play Dice?
Schooling :
Kendriya Vidyalaya No. 1, Ambala Cantonment, 1975-79
Kendriya Vidyalaya, BHU Varanasi, 1974-75
Kendriya Vidayala, Babina Cantonment, 1973-74
Shalini Preparatory School, Clement Town, Dehradun, 1969-72