Notice Board

N-steps closer towards testing the theory of everything

Unifying quantum mechanics and gravity is the holy grail of theoretical physics. Many versions of this final theory or the theory of everything, such as String Theory and Loop Quantum Gravity have been proposed, yet none have been experimentally verified, owing to the extreme high energies (a million billion times the energy reached in the Large Hadron Collider) required to do so directly. A recent proposal by physicists in Vienna and London, and published in the Journal Nature Physics in 2012 [1] showed that verification of certain features of the theory, although still difficult, may in fact be possible in optical interferometers, and at energies accessible in laboratories. Two authors of the above, Igor Pikovski (Harvard) and Michael Vanner (Oxford) and Pasquale Bosso, a recent Ph.D. from the University of Lethbridge and Saurya Das of the Department of Physics and Astronomy extended this proposal to show that these "quantum gravity signals" can be amplified significantly, by letting the interferometer laser circulate N (a large number of) times, while keeping noise levels to a minimum. Thus in principle one is much closer to obtaining experimental signatures of the theory of everything. If such signatures are indeed found by experimentalists, they would provide one of the first hints of the true nature of quantum gravity as well as the fundamental nature of space and time. This work has now been published in the journal Physical Review A [2]. We mention that some of the theoretical work which formed the basis of the 2012 Nature Physics paper, was done by Das, his collaborators Ahmed Farag Ali, who is also a graduate from the University of Lethbridge and Elias Vagenas of Kuwait University, and was published in the journals Physical Review Letters [3], Physical Review D [4] and Physics Letters B [5].

[1] I. Pikovski, M. R. Vanner, M. Aspelmeyer, M. S. Kim, C. Brukner, “Probing Planck-scale physics with quantum optics”, Nature Physics 8, 393-397 (2012); doi:10.1038/nphys2262. 

[2] P. Bosso, S. Das, I. Pikovski, M. Vanner, “Amplified transduction of Planck-scale effects using quantum optics”, to appear in Physical Review A96, 023849 (2017); https://doi.org/10.1103/PhysRevA.96.023849. 

[3] S. Das, E. C. Vagenas, “Universality of quantum gravity corrections”, Physical Review Letters 101, 221301 (2008);https://doi.org/10.1103/PhysRevLett.101.221301.

[4] A. F. Ali, S. Das, E. C. Vagenas, “Proposal for testing quantum gravity in the lab”, Physical Review D84, 044013 (2011); https://doi.org/10.1103/PhysRevD.84.044013.

[5] A. F. Ali, S. Das, E. C. Vagenas, “Discreteness of space from the generalized uncertainty principle”, Physics LettersB678, 497-499 (2009); https://doi.org/10.1016/j.physletb.2009.06.061.