The previous episode of “this week-ish” was posted on June 5. Its been six months since then. I guess its time to post another volume but to be fair the title of this post has been changed to reflect the longer time span its contents refer to.
Table of Contents
Gravity as Quantum Computation (contd from Vol. 1)
In the previous episode of “this week-ish” I wrote about the emerging relationship between quantum computation and quantum gravity, especially with regards to a recent paper by Caputa and Magan [1]. A recent paper [2] has approached this problem from a slightly different perspective.
In [1] and related works the method pioneered by Nielsen is used to argue that gravity sets the rules for optimal quantum computation. I will elaborate on the idea behind these approaches in another post. Taken together all these works add greater weight to what I like to call the computational universe hypothesis – the premise that all physical phenomena can be viewed as computational processes and that moreover the particle content of our Universe is precisely such that it provides the minimum number of elementary gates needed for universal quantum computation. More on this in a later post.
Quantum Channels as Thermal Engines
Bringing quantum information still closer to statistical mechanics and thermodynamics comes this exciting paper [3] which suggests that one should view quantum channels – essentially operators which map one quantum system into another – as thermodynamic objects with which one can associate a unique quantity called the thermodynamic capacity. The physical interpretation of this quantity is, I quote: “the work required to simulate many repetitions of a quantum process employing many repetitions of another quantum process becomes equal to the difference of the respective thermodynamic capacities.”
Experimental Evidence for Lorentz Violation
This [4] is probably one of the most exciting experimental results in recent memory. Lorentz invariance is one of the sacred cornerstones of modern theoretical physics and theories such as loop quantum gravity have often been shrugged off because of the (misguided) belief that discrete quantum geometry is not compatible with microscopic Lorentz invariance. Such beliefs were only strengthened by the negative results of searches for Lorentz violation using the Fermi space telescope [5]. It is therefore very gratifying to see published works which point out that (possible) Lorentz violation has already been see by the neutrino observatory known as IceCube. Unverified reports suggest that on finding traces of Lorentz violation the IceCube scientists were heard to yell out “it was a good day!”
Loops ’19: Fun with Kac-Moody algebras and quantum error correction
And, finally, we come to what was without a doubt the most exciting event of 2019. Loops’ 19 – the biannual meeting where loop quantum gravity people from all over the globe gather together to plot the overthrow of string theory (muahahahaha) – was held at Penn State. Surprisingly enough my abstract was selected for a parallel talk. Even more surprising was the fact that I managed to make it there at all given the bureaucratic maze called “life” here in India, which I had to navigate through!
It was my first time attending Loops, which made especially wonderful by the fact that Penn State is where I did my PhD. And, no, it was NOT with Abhay as my advisor if you must ask!
My talk was on recent work I have done relating quantum error correction to diffeomorphism invariance of spin networks. Essentially my claim is that LQG naturally incorporates quantum error correcting codes in the form of “noiseless subsystems” [6, 7, 8] which, conveniently enough can also be viewed as elementary particles [9, 10, 11, 12, 13, 14, 15, 16]. As chance would have it Laurent Freidel presented his most recent work (with Daniele Pranzetti and Etera Livine) [17] in an earlier parallel talk. I did have the chance to point out that their idea of replacing spin network edges with tubes was not exactly new and that several other researchers, including me, had suggested the same picture long before their own work. Apparently they were not in the mood to humour my claims of precendence.
The response is understandable. As a leading LQG researcher recently pointedly mentioned: “[my] papers are unpublished and almost uncited” and moreover, referring to one of my papers,”[it] is rather messy, mixing well-known physics (Hall effect) with original ideas and known ideas (and even almost wrong ideas), all on equal footing.” Given this prior feedback I was not surprised by the lack of a response.
But, I digress.
What matters is that, after much procrastinating, I have finally put my ideas down in another – hopefully not so “messy” – paper [18]. I cannot be held guilty of being either a great fan of, or even being very capable of, mathematical rigor. Thus, those looking for page upon page of math will be disappointed. The physical picture is, however, I believe very clear. I would love to hear more from anybody who does find the time to look through my work.
That’s all folks. Wishing you all a very happy new year. I leave you with some wonderful memories from Loops’ 19.
[1] ![[doi]](https://i0.wp.com/www.quantumofgravity.com/blog/wp-content/plugins/papercite/img/external.png?resize=10%2C10&ssl=1)
P. Caputa and J. M. Magan, “Quantum Computation as Gravity,” Physical review letters, vol. 122, iss. 23, p. 231302, 2019.
[Bibtex]
P. Caputa and J. M. Magan, “Quantum Computation as Gravity,” Physical review letters, vol. 122, iss. 23, p. 231302, 2019. [Bibtex]
@article{Caputa2019Quantum,
abstract = {We formulate Nielsen's geometric approach to complexity in the context of two dimensional conformal field theories, where series of conformal transformations are interpreted as unitary circuits. We show that the complexity functional can be written as the Polyakov action of two dimensional gravity or, equivalently, as the geometric action on the coadjoint orbits of the Virasoro group. This way, we argue that gravity sets the rules for optimal quantum computation in conformal field theories.},
archiveprefix = {arXiv},
author = {Caputa, Pawel and Magan, Javier M.},
date-added = {2024-08-25 13:27:16 +0530},
date-modified = {2024-08-25 13:27:16 +0530},
doi = {10.1103/PhysRevLett.122.231302},
eprint = {1807.04422},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Caputa\;Magan_Quantum Computation as Gravity_2019.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/JG6GKJ76/1807.html},
issn = {0031-9007, 1079-7114},
journal = {Physical Review Letters},
keywords = {High Energy Physics - Theory,Quantum Physics},
month = jun,
number = {23},
pages = {231302},
primaryclass = {hep-th, physics:quant-ph},
title = {Quantum {{Computation}} as {{Gravity}}},
urldate = {2024-08-25},
volume = {122},
year = {2019},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.122.231302}}[2] H. A. Camargo, M. P. Heller, R. Jefferson, and J. Knaute, “Path integral optimization as circuit complexity,” Physical review letters, vol. 123, iss. 1, p. 11601, 2019.
[Bibtex]
H. A. Camargo, M. P. Heller, R. Jefferson, and J. Knaute, “Path integral optimization as circuit complexity,” Physical review letters, vol. 123, iss. 1, p. 11601, 2019. [Bibtex]
@article{Camargo2019Path,
abstract = {Early efforts to understand complexity in field theory have primarily employed a geometric approach based on the concept of circuit complexity in quantum information theory. In a parallel vein, it has been proposed that certain deformations of the Euclidean path integral that prepares a given operator or state may provide an alternative definition, whose connection to the standard notion of complexity is less apparent. In this letter, we bridge the gap between these two proposals in two-dimensional conformal field theories, by explicitly showing how the latter approach from path integral optimization may be given a concrete realization within the standard gate counting framework. In particular, we show that when the background geometry is deformed by a Weyl rescaling, a judicious gate counting allows one to recover the Liouville action as a particular choice within a more general class of cost functions.},
archiveprefix = {arXiv},
author = {Camargo, Hugo A. and Heller, Michal P. and Jefferson, Ro and Knaute, Johannes},
date-added = {2024-08-25 13:30:01 +0530},
date-modified = {2024-08-25 13:30:01 +0530},
doi = {10.1103/PhysRevLett.123.011601},
eprint = {1904.02713},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Camargo\;Heller\;Jefferson\;Knaute_Path integral optimization as circuit complexity_2019.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/PMBQKDQE/Camargo et al. - 2019 - Path integral optimization as circuit complexity.pdf},
issn = {0031-9007, 1079-7114},
journal = {Physical Review Letters},
keywords = {High Energy Physics - Theory,Quantum Physics},
month = jul,
number = {1},
pages = {011601},
primaryclass = {hep-th, physics:quant-ph},
title = {Path Integral Optimization as Circuit Complexity},
urldate = {2024-08-25},
volume = {123},
year = {2019},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.123.011601}}[3] P. Faist, M. Berta, and F. Brandão, “Thermodynamic Capacity of Quantum Processes,” Physical review letters, vol. 122, iss. 20, p. 200601, 2019.
[Bibtex]
P. Faist, M. Berta, and F. Brandão, “Thermodynamic Capacity of Quantum Processes,” Physical review letters, vol. 122, iss. 20, p. 200601, 2019. [Bibtex]
@article{Faist2019Thermodynamic,
abstract = {Thermodynamics imposes restrictions on what state transformations are possible. In the macroscopic limit of asymptotically many independent copies of a state---as for instance in the case of an ideal gas---the possible transformations become reversible and are fully characterized by the free energy. In this Letter, we present a thermodynamic resource theory for quantum processes that also becomes reversible in the macroscopic limit, a property that is especially rare for a resource theory of quantum channels. We identify a unique single-letter and additive quantity, the thermodynamic capacity, that characterizes the "thermodynamic value" of a quantum channel, in the sense that the work required to simulate many repetitions of a quantum process employing many repetitions of another quantum process becomes equal to the difference of the respective thermodynamic capacities. On a technical level, we provide asymptotically optimal constructions of universal implementations of quantum processes. A challenging aspect of this construction is the apparent necessity to coherently combine thermal engines that would run in different thermodynamic regimes depending on the input state. Our results have applications in quantum Shannon theory by providing a generalized notion of quantum typical subspaces and by giving an operational interpretation to the entropy difference of a channel.},
archiveprefix = {arXiv},
author = {Faist, Philippe and Berta, Mario and Brand{\~a}o, Fernando},
date-added = {2024-08-25 13:30:45 +0530},
date-modified = {2024-08-25 13:30:45 +0530},
doi = {10.1103/PhysRevLett.122.200601},
eprint = {1807.05610},
file = {/Volumes/Data/owncloud/root/research/zotero/storage/DLBJHJ8P/Faist et al. - 2019 - Thermodynamic Capacity of Quantum Processes.pdf},
issn = {0031-9007, 1079-7114},
journal = {Physical Review Letters},
keywords = {Quantum Physics},
month = may,
number = {20},
pages = {200601},
primaryclass = {quant-ph},
title = {Thermodynamic {{Capacity}} of {{Quantum Processes}}},
urldate = {2024-08-25},
volume = {122},
year = {2019},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.122.200601}}[4] Y. Huang, H. Li, and B. Ma, “Consistent Lorentz violation features from near-TeV IceCube neutrinos,” Physical review d, vol. 99, iss. 12, p. 123018, 2019.
[Bibtex]
Y. Huang, H. Li, and B. Ma, “Consistent Lorentz violation features from near-TeV IceCube neutrinos,” Physical review d, vol. 99, iss. 12, p. 123018, 2019. [Bibtex]
@article{Huang2019Consistent,
abstract = {A recent proposal to associate 60{\textasciitilde}TeV to 2{\textasciitilde}PeV IceCube neutrino events with gamma-ray bursts{\textasciitilde}(GRBs) indicates the Lorentz violation of cosmic neutrinos and leads further to the \$CPT\$ symmetry violation between neutrinos and antineutrinos. Here we find that another 12 northern hemisphere track events possibly correlated with GRBs from three-year IceCube data satisfy the same regularity at a lower energy scale around 1{\textasciitilde}TeV. The combined fitting indicates a Lorentz violation scale \$\{E\}\_\{{\textbackslash}rm LV\}=(6.4{\textbackslash}pm 1.5){\textbackslash}times10{\textasciicircum}\{17\}{\textasciitilde}\{ {\textbackslash}rm GeV\}\$ and an intrinsic time difference \$\{{\textbackslash}Delta \{t\}\_\{{\textbackslash}rm in\}=(-2.8{\textbackslash}pm 0.7){\textbackslash}times10{\textasciicircum}2{\textasciitilde}\{{\textbackslash}rm s\}\}\$, from which we find an earlier emission of neutrinos than photons at the GRB source. We also suggest analyzing neutrino events detected a few minutes before the GRB trigger time to test the \$CPT\$ violation of ultrahigh-energy neutrinos.},
archiveprefix = {arXiv},
author = {Huang, Yanqi and Li, Hao and Ma, Bo-Qiang},
date-added = {2024-08-25 13:32:18 +0530},
date-modified = {2024-08-25 13:32:18 +0530},
doi = {10.1103/PhysRevD.99.123018},
eprint = {1906.07329},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Huang\;Li\;Ma_Consistent Lorentz violation features from near-TeV IceCube neutrinos_2019.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/2323SIQR/Huang et al. - 2019 - Consistent Lorentz violation features from near-Te.pdf},
issn = {2470-0010, 2470-0029},
journal = {Physical Review D},
keywords = {Astrophysics - High Energy Astrophysical Phenomena,General Relativity and Quantum Cosmology,High Energy Physics - Phenomenology},
month = jun,
number = {12},
pages = {123018},
primaryclass = {astro-ph, physics:gr-qc, physics:hep-ph},
title = {Consistent {{Lorentz}} Violation Features from Near-{{TeV IceCube}} Neutrinos},
urldate = {2024-08-25},
volume = {99},
year = {2019},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevD.99.123018}}[5] R. J. Nemiroff, R. Connolly, J. Holmes, and A. B. Kostinski, “Bounds on spectral dispersion from Fermi-detected gamma ray bursts,” Physical review letters, vol. 108, iss. 23, 2012.
[Bibtex]
R. J. Nemiroff, R. Connolly, J. Holmes, and A. B. Kostinski, “Bounds on spectral dispersion from Fermi-detected gamma ray bursts,” Physical review letters, vol. 108, iss. 23, 2012. [Bibtex]
@article{Nemiroff2012Bounds,
abstract = {Data from four Fermi-detected gamma-ray bursts (GRBs) are used to set limits on spectral dispersion of electromagnetic radiation across the Universe. The analysis focuses on photons recorded above 1 GeV for Fermi-detected GRB 080916C, GRB 090510A, GRB 090902B, and GRB 090926A because these high-energy photons yield the tightest bounds on light dispersion. It is shown that significant photon bunches in GRB 090510A, possibly classic GRB pulses, are remarkably brief, an order of magnitude shorter in duration than any previously claimed temporal feature in this energy range. Although conceivably a{$>$}3{$\sigma$} fluctuation, when taken at face value, these pulses lead to an order of magnitude tightening of prior limits on photon dispersion. Bound of {$\Delta$}c/c{$<$}6.94{\texttimes}10(-21) is thus obtained. Given generic dispersion relations where the time delay is proportional to the photon energy to the first or second power, the most stringent limits on the dispersion strengths were k1{$<$}1.61{\texttimes}10(-5)\,\,sec\,Gpc(-1)\,GeV(-1) and k2{$<$}3.57{\texttimes}10(-7)\,\,sec\,Gpc(-1)\,GeV(-2), respectively. Such limits constrain dispersive effects created, for example, by the spacetime foam of quantum gravity. In the context of quantum gravity, our bounds set M1c(2) greater than 525 times the Planck mass, suggesting that spacetime is smooth at energies near and slightly above the Planck mass.},
archiveprefix = {arXiv},
author = {Nemiroff, Robert J. and Connolly, Ryan and Holmes, Justin and Kostinski, Alexander B.},
doi = {10.1103/PhysRevLett.108.231103},
eprint = {1109.5191},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Nemiroff;Connolly;Holmes;Kostinski_Bounds on spectral dispersion from Fermi-detected gamma ray bursts_2012.pdf},
issn = {00319007},
journal = {Physical Review Letters},
keywords = {dispersion,experiment,fermi_telescope,gamma_ray_bursts,lorentz_violation,observational,quantum_geometry,quantum_gravity},
month = apr,
number = {23},
pmid = {23003941},
title = {Bounds on Spectral Dispersion from {{Fermi-detected}} Gamma Ray Bursts},
volume = {108},
year = {2012},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.108.231103}}[6] P. Zanardi and M. Rasetti, "Noiseless Quantum Codes," Physical review a, vol. 79, iss. 17, p. 4, 1997.
[Bibtex]
P. Zanardi and M. Rasetti, "Noiseless Quantum Codes," Physical review a, vol. 79, iss. 17, p. 4, 1997. [Bibtex]
@article{Zanardi1997Noiseless,
abstract = {In this paper we study a model quantum register \${\textbackslash}cal R\$ made of \$N\$ replicas (cells) of a given finite-dimensional quantum system S. Assuming that all cells are coupled with a common environment with equal strength we show that, for \$N\$ large enough, in the Hilbert space of \${\textbackslash}cal R\$ there exists a linear subspace \$\{{\textbackslash}cal C\}\_N\$ which is dynamically decoupled from the environment. The states in \$\{{\textbackslash}cal C\}\_N\$ evolve unitarily and are therefore decoherence-dissipation free. The space \$\{{\textbackslash}cal C\}\_N\$ realizes a noiseless quantum code in which information can be stored, in principle, for arbitrarily long time without being affected by errors.},
archiveprefix = {arXiv},
author = {Zanardi, P. and Rasetti, M.},
date-modified = {2024-08-25 13:14:16 +0530},
doi = {10.1103/PhysRevLett.79.3306},
eprint = {quant-ph/9705044},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Zanardi;Rasetti_Noiseless Quantum Codes_1997.pdf},
isbn = {10.1142/S0217984997001304},
issn = {0031-9007},
journal = {Physical Review A},
keywords = {decoherence,file-import-09-12-27,nosource,quantum_code,quantum-computation},
number = {17},
pages = {4},
pmid = {25978211},
publisher = {American Physical Society},
title = {Noiseless {{Quantum Codes}}},
type = {Journal Article},
volume = {79},
year = {1997},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.79.3306}}@article{Kribs2005Geometry,
abstract = {We investigate the possibility that a background independent quantum theory of gravity is not a theory of quantum geometry. We provide a way for global spacetime symmetries to emerge from a background independent theory without geometry. In this, we use a quantum information theoretic formulation of quantum gravity and the method of noiseless subsystems in quantum error correction. This is also a method that can extract particles from a quantum geometric theory such as a spin foam model.},
archiveprefix = {arXiv},
author = {Kribs, David W. and Markopoulou, Fotini},
eprint = {gr-qc/0510052},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Kribs;Markopoulou_Geometry from quantum particles_2005.pdf},
journal = {arXiv},
keywords = {computational_universe,error_correction,fotini,General Relativity and Quantum Cosmology,High Energy Physics - Theory,noiseless_subsystems,quantum_computation,quantum_geometry,quantum_gravity,spin-foams},
month = oct,
pages = {17},
title = {Geometry from Quantum Particles},
year = {2005}}[8] D. Kribs, R. Laflamme, and D. Poulin, "Unified and generalized approach to quantum error correction," Physical review letters, vol. 94, iss. 18, 2005.
[Bibtex]
D. Kribs, R. Laflamme, and D. Poulin, "Unified and generalized approach to quantum error correction," Physical review letters, vol. 94, iss. 18, 2005. [Bibtex]
@article{Kribs2005Unified,
abstract = {We present a unified approach to quantum error correction, called operator quantum error correction. This scheme relies on a generalized notion of noiseless subsystems that is not restricted to the commutant of the interaction algebra. We arrive at the unified approach, which incorporates the known techniques -- i.e. the standard error correction model, the method of decoherence-free subspaces, and the noiseless subsystem method -- as special cases, by combining active error correction with this generalized noiseless subsystem method. Moreover, we demonstrate that the quantum error correction condition from the standard model is a necessary condition for all known methods of quantum error correction.},
author = {Kribs, David and Laflamme, Raymond and Poulin, David},
doi = {10.1103/PhysRevLett.94.180501},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Kribs;Laflamme;Poulin_Unified and generalized approach to quantum error correction_22.pdf},
issn = {0031-9007},
journal = {Physical Review Letters},
month = dec,
number = {18},
title = {Unified and Generalized Approach to Quantum Error Correction},
volume = {94},
year = {2005},
bdsk-url-1 = {https://doi.org/10.1103/PhysRevLett.94.180501}}[9] S. O. {Bilson-Thompson}, "A topological model of composite preons," Arxiv preprint hep-ph/0503213, iss. December 2005, p. 6, 2005.
[Bibtex]
[Bibtex]
@article{Bilson-Thompson2005A-Topological,
abstract = {We describe a simple model, based on the preon model of Shupe and Harari, in which the binding of preons is represented topologically. We then demonstrate a direct correspondence between this model and much of the known phenomenology of the Standard Model. In particular we identify the substructure of quarks, leptons and gauge bosons with elements of the braid group \$B\_3\$. Importantly, the preonic objects of this model require fewer assumed properties than in the Shupe/Harari model, yet more emergent quantities, such as helicity, hypercharge, and so on, are found. Simple topological processes are identified with electroweak interactions and conservation laws. The objects which play the role of preons in this model may occur as topological structures in a more comprehensive theory, and may themselves be viewed as composite, being formed of truly fundamental sub-components, representing exactly two levels of substructure within quarks and leptons.},
archiveprefix = {arXiv},
author = {{Bilson-Thompson}, Sundance O.},
date-modified = {2024-08-25 13:14:12 +0530},
eprint = {hep-ph/0503213},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Bilson-Thompson_A topological model of composite preons_22.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/UU8J9YQA/Bilson-Thompson_A topological model of composite preons_2005.pdf},
journal = {arXiv preprint hep-ph/0503213},
keywords = {_tablet,10,12,60,braids,composite models,dm,model,pacs,preons,rc,standard,topology},
month = mar,
number = {December 2005},
pages = {6},
title = {A Topological Model of Composite Preons},
type = {Electronic Citation},
year = {2005}}[10] S. O. {Bilson-Thompson}, F. Markopoulou, and L. Smolin, "Quantum gravity and the standard model," , 2006.
[Bibtex]
[Bibtex]
@article{Bilson-Thompson2006Quantum,
abstract = {We show that a class of background independent models of quantum spacetime have local excitations that can be mapped to the first generation fermions of the standard model of particle physics. These states propagate coherently as they can be shown to be noiseless subsystems of the microscopic quantum dynamics. These are identified in terms of certain patterns of braiding of graphs, thus giving a quantum gravitational foundation for the topological preon model proposed by one of us. {$<$}br /{$>$}These results apply to a large class of theories in which the Hilbert space has a basis of states given by ribbon graphs embedded in a three-dimensional manifold up to diffeomorphisms, and the dynamics is given by local moves on the graphs, such as arise in the representation theory of quantum groups. For such models, matter appears to be already included in the microscopic kinematics and dynamics.},
author = {{Bilson-Thompson}, S O and Markopoulou, F and Smolin, L},
date-modified = {2024-08-25 13:14:05 +0530},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Bilson-Thompson\;Markopoulou\;Smolin_Quantum gravity and the standard model_22.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/SGPNU4JQ/Bilson-Thompson\;Markopoulou\;Smolin_Quantum gravity and the standard model_2006.pdf},
keywords = {_tablet,braids,file-import-09-12-27,gravity,model,preons,quantum,spin foams,standard,three dimensions,topology},
month = mar,
title = {Quantum Gravity and the Standard Model},
type = {Electronic Citation},
year = {2006}}[11] J. Hackett, "Invariants of Braided Ribbon Networks," , 2011.
[Bibtex]
[Bibtex]
@article{Hackett2011Invariants,
abstract = {We present a consistent definition for braided ribbon networks in 3-dimensional manifolds, unifying both three and four valent networks in a single framework. We present evolution moves for these networks which are dual to the Pachner moves on simplices and present an invariant of this evolution. Finally we relate these results back to previous work in the subject.},
author = {Hackett, Jonathan},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Hackett_Invariants of Braided Ribbon Networks_22.pdf},
keywords = {bilson-thompson,braids,jonathan_hackett,pachner_moves,quantum_gravity,simplicial_geometry,topological_invariant},
month = jun,
title = {Invariants of {{Braided Ribbon Networks}}},
year = {2011}}[12] J. Hackett, "Invariants of Spin Networks from Braided Ribbon Networks," , 2011.
[Bibtex]
[Bibtex]
@article{Hackett2011bInvariants,
abstract = {We connect Braided Ribbon Networks to the states of loop quantum gravity. Using this connection we present the reduced link as an invariant which captures information from the embedding of the spin-networks. We also present a means of understanding higher valent nodes in the context of braided ribbon networks and an interpretation of the dual of these nodes as polygons or polyhedra.},
archiveprefix = {arXiv},
author = {Hackett, Jonathan},
eprint = {1106.5095},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Hackett_Invariants of Spin Networks from Braided Ribbon Networks_2011.pdf},
keywords = {bilson-thompson,braids,geometry,jonathan_hackett,linking,lqg,pachner_moves,quantum_gravity,simplicial_geometry,standard_model,topological_invariant},
month = jun,
title = {Invariants of {{Spin Networks}} from {{Braided Ribbon Networks}}},
year = {2011}}[13] Y. Wan, "On Braid Excitations in Quantum Gravity," , p. 24, 2007.
[Bibtex]
[Bibtex]
@article{Wan2007On-Braid,
abstract = {We propose a new notation for the states in some models of quantum gravity, namely 4-valent spin networks embedded in a topological three manifold. With the help of this notation, equivalence moves, namely translations and rotations, can be defined, which relate the projections of diffeomorphic embeddings of a spin network. Certain types of topological structures, viz 3-strand braids as local excitations of embedded spin networks, are defined and classified by means of the equivalence moves. This paper formulates a mathematical approach to the further research of particle-like excitations in quantum gravity.},
archiveprefix = {arXiv},
author = {Wan, Yidun},
date-modified = {2024-08-25 13:14:16 +0530},
eprint = {0710.1312},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Wan_On Braid Excitations in Quantum Gravity_22.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/5JMIWPV9/Wan_On Braid Excitations in Quantum Gravity_2007.pdf},
keywords = {_tablet,braids,elementary,file-import-09-12-27,gravity,model,particles,quantum,standard},
month = oct,
pages = {24},
title = {On {{Braid Excitations}} in {{Quantum Gravity}}},
type = {Journal Article},
year = {2007}}[14] Y. Wan, "Effective theory of braid excitations of quantum geometry in terms of Feynman diagrams," Nuclear physics b, vol. 814, iss. 1-2, p. 1–20, 2009.
[Bibtex]
Y. Wan, "Effective theory of braid excitations of quantum geometry in terms of Feynman diagrams," Nuclear physics b, vol. 814, iss. 1-2, p. 1–20, 2009. [Bibtex]
@article{Wan2009Effective,
abstract = {We study interactions amongst topologically conserved excitations of quantum theories of gravity, in particular the braid excitations of four valent spin networks. These have been shown previously to propagate and interact under evolution rules of spin foam models. We show that the dynamics of these braid excitations can be described by an effective theory based on Feynman diagrams. In this language, braids which are actively interacting are analogous to bosons, in that the topological conservation laws permit them to be singly created and destroyed. Exchanges of these excitations give rise to interactions between braids which are charged under the topological conservation rules. {\copyright} 2009 Elsevier B.V. All rights reserved.},
archiveprefix = {arXiv},
author = {Wan, Yidun},
doi = {10.1016/j.nuclphysb.2008.10.025},
eprint = {0809.4464},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Wan_Effective theory of braid excitations of quantum geometry in terms of Feynman_22.pdf;/Volumes/Data/owncloud/root/research/zotero/storage/PC6J6E9Y/Wan_Effective Theory of Braid Excitations of Quantum Geometry in terms of Feynman_2009.pdf},
issn = {05503213},
journal = {Nuclear Physics B},
keywords = {_tablet,braids,effective-theory,elementary_particles,feynman_graphs,quantum_geometry,topology,yidun_wan},
month = jan,
number = {1-2},
pages = {1--20},
title = {Effective Theory of Braid Excitations of Quantum Geometry in Terms of {{Feynman}} Diagrams},
volume = {814},
year = {2009},
bdsk-url-1 = {https://doi.org/10.1016/j.nuclphysb.2008.10.025}}[15] D. Vaid, "Embedding the Bilson-Thompson Model in a LQG-like framework," , p. 1–10, 2010.
[Bibtex]
[Bibtex]
@article{Vaid2010Embedding,
abstract = {We argue that the Quadratic Spinor Lagrangian approach allows us to approach the problem of forming a geometrical condensate of spinorial tetrads in a natural manner. This, along with considerations involving the discrete symmetries of lattice triangulations, lead us to discover that the quasiparticles of such a condensate are tetrahedra with braids attached to its faces and that these braid attachments correspond to the preons in Bilson-Thompson's model of elementary particles. These "spatoms" can then be put together in a tiling to form more complex structures which encode both geometry and matter in a natural manner. We conclude with some speculations on the relation between this picture and the computational universe hypothesis.},
archiveprefix = {arXiv},
author = {Vaid, Deepak},
eprint = {1002.1462v1},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Vaid_Embedding the Bilson-Thompson Model in a LQG-like framework_2010.pdf},
keywords = {bilson-thompson,bilson-thompson model,braids,computational_universe,condensate,defects,discrete-symmetries,elementary_particles,many body,preons,quadratic-spinor-lagrangian,quantum gravity,quantum_gravity,standard_model,topology,vaid_deepak},
month = feb,
pages = {1--10},
title = {Embedding the {{Bilson-Thompson Model}} in a {{LQG-like}} Framework},
year = {2010}}[16] D. Vaid, "Elementary Particles as Gates for Universal Quantum Computation," , p. 8, 2013.
[Bibtex]
[Bibtex]
@article{Vaid2013Elementary,
abstract = {It is shown that there exists a mapping between the fermions of the Standard Model (SM) represented as braids in the Bilson-Thompson model, and a set of gates which can perform Universal Quantum Computation (UQC). This leads us to conjecture that the "Computational Universe Hypothesis" (CUH) can be given a concrete implementation in a new physical framework where elementary particles and the gauge bosons (which intermediate interactions between fermions) are interpreted as the components of a quantum computational network, with the particles serving as quantum computational gates and the gauge fields as the information carrying entities.},
archiveprefix = {arXiv},
author = {Vaid, Deepak},
eprint = {1307.0096},
file = {/Users/deepak/ownCloud/root/research/zotero_pdfs/Vaid_Elementary Particles as Gates for Universal Quantum Computation_2013.pdf},
keywords = {bilson-thompson,braids,computational_universe,fqxi,large_gauge_transformation,lqg,preons,quantum_computation,quantum_gates,quantum_gravity,universal,vaid_d},
month = jun,
pages = {8},
title = {Elementary {{Particles}} as {{Gates}} for {{Universal Quantum Computation}}},
year = {2013}}[17] L. Freidel, E. R. Livine, and D. Pranzetti, "Gravitational edge modes: From Kac-Moody charges to Poincar\${\textbackslash}backslash\$'e networks," , 2019.
[Bibtex]
[Bibtex]
@article{Freidel2019Gravitational,
abstract = {We revisit the canonical framework for general relativity in its connection-vierbein formulation, recasting the Gauss law, the Bianchi identity and the space diffeomorphism bulk constraints as conservation laws for boundary surface charges, respectively electric, magnetic and momentum charges. Partitioning the space manifold into 3D regions glued together through their interfaces, we focus on a single domain and its punctured 2D boundary. The punctures carry a ladder of Kac-Moody edge modes, whose 0-modes represent the electric and momentum charges while the higher modes describe the stringy vibration modes of the 1D-boundary around each puncture. In particular, this allows to identify missing observables in the discretization scheme used in loop quantum gravity and leads to an enhanced theory upgrading spin networks to tube networks carrying Virasoro representations. In the limit where the tubes are contracted to 1D links and the string modes neglected, we do not just recover loop quantum gravity but obtain a more general structure: Poincar\${\textbackslash}backslash\$'e charge networks, which carry a representation of the 3D diffeomorphism boundary charges on top of the \${\textbackslash}backslashmathrm\{SU\}(2)\$ fluxes and gauge transformations.},
author = {Freidel, Laurent and Livine, Etera R. and Pranzetti, Daniele},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Freidel;Livine;Pranzetti_Gravitational edge modes - From Kac-Moody charges to Poincar$-backslash$'e_2019.pdf},
month = jun,
title = {Gravitational Edge Modes: {{From Kac-Moody}} Charges to {{Poincar}}\${\textbackslash}backslash\$'e Networks},
year = {2019}}[18] D. Vaid, "Quantum Error Correction in Loop Quantum Gravity," , 2019.
[Bibtex]
[Bibtex]
@article{Vaid2019Quantum,
abstract = {Previous works (by Almiehri, Dong, Harlow, Pastakawski, Preskill, Yoshida and others) have established that quantum error correction plays an important role in understanding how the bulk degrees of freedom of an Anti-deSitter spacetime are encoded in the degrees of freedom of the boundary Conformal Field Theory. In previous work \${\textbackslash}backslash\$cite\{Vaid2013Elementary\} I have argued that the Bilson-Thompson model \${\textbackslash}backslash\$cite\{Bilson-Thompson2006Quantum,Vaid2010Embedding\} of elementary particles allows us to view elementary particles as gates for universal quantum computation. In the present work I show that the Bilson-Thompson model, where elementary particles are represented by elements of the framed braid group on three strands, provides an explicit model for the generation of qutrit (three-qubit) states which are the ingredients of Shor's quantum error correcting code. This allows, for the first time, to connect in a concrete manner the proposals of Almheiri, Pastawski, Preskill and others regarding the role of quantum error correction in quantum gravity, to a viable model of elementary particles. Loop Quantum Gravity (LQG), the theory of quantum gravity in which such topological excitations exist, can thus serve as the glue which can connect AdS/CFT based approaches to quantum gravity to the well understood physics of the Standard Model.},
author = {Vaid, Deepak},
file = {/Volumes/Data/owncloud/root/research/zotero_pdfs/Vaid_Quantum Error Correction in Loop Quantum Gravity_22.pdf},
title = {Quantum {{Error Correction}} in {{Loop Quantum Gravity}}},
year = {2019}}