The DOI matches its Crossref record; 36 of the 36 references it cites were found in a registry or an index.
Computational Capacity of the Universe
Open accessAbstract
All physical systems register and process information. The laws of physics determine the amount of information that a physical system can register (number of bits) and the number of elementary logic operations that a system can perform (number of ops). The Universe is a physical system. The amount of information that the Universe can register and the number of elementary operations that it can have performed over its history are calculated. The Universe can have performed ${10}^{120}\phantom{\rule{0ex}{0ex}}\mathrm{ops}$ on ${10}^{90}\phantom{\rule{0ex}{0ex}}\mathrm{bits}$ ( ${10}^{120}\phantom{\rule{0ex}{0ex}}\mathrm{bits}$ including gravitational degrees of freedom).
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The check wasn’t confident either way, so it gives no verdict — never disputed.
In the citing paper
“We consider Hamiltonians that can be written as a polynomial number of terms, with respect to the system size.”
From A variational eigenvalue solver on a photonic quantum processor (2014) · cites this paper as [20]
Experimental — accuracy not yet measuredThe check wasn’t confident either way, so it gives no verdict — never disputed.
In the citing paper
“This class of Hamiltonians encompasses a wide range of physical systems, including the electronic structure Hamiltonian of quantum chemistry, the quantum Ising Model, the Heisenberg Model2021, matrices that are well approximated as a sum of n-fold tensor products2223, and more generally any k-sparse Hamiltonian without evident tensor product structure”
From A variational eigenvalue solver on a photonic quantum processor (2014) · cites this paper as [20]
Experimental — accuracy not yet measuredIn the citing paper
“According to Uhlmann's theorem [18], the square root of the fidelity is given by”
From Geometric derivation of the quantum speed limit (2010) · cites this paper as [18]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Susskind, L. (1995) · Journal of Mathematical Physics · doi:10.1063/1.531249 · Cited by 4,085
Lloyd, S. (1996) · Science · doi:10.1126/science.273.5278.1073 · Cited by 3,088
Self-citationPrinciples of physical cosmology
(1993) · Choice Reviews Online · doi:10.5860/choice.31-1499 · Cited by 2,908
M theory as a matrix model: A conjecture
Banks, T., Fischler, W., Shenker, S. H., & Susskind, L. (1997) · Physical Review D · doi:10.1103/physrevd.55.5112 · Cited by 2,748
Quantum Theory: Concepts and Methods
Peres, A., & Ballentine, L. E. (1995) · American Journal of Physics · doi:10.1119/1.17946 · Cited by 2,561
Proceedings of the 56th Annual ACM Symposium on Theory of Computing
(2024) · doi:10.1145/3618260 · Cited by 1,843
Particle Physics and Inflationary Cosmology
Linde, A. D. (1987) · Physics Today · doi:10.1063/1.881088 · Cited by 1,805
Demonstration of a Fundamental Quantum Logic Gate
Monroe, C., Meekhof, D. M., King, B. E., Itano, W. M., & Wineland, D. J. (1995) · Physical Review Letters · doi:10.1103/physrevlett.75.4714 · Cited by 1,586
Bulk Spin-Resonance Quantum Computation
Gershenfeld, N. A., & Chuang, I. L. (1997) · Science · doi:10.1126/science.275.5298.350 · Cited by 1,528
Particle Physics and Inflationary Cosmology
Linder, C. (1990) · CRC Press eBooks · doi:10.1201/b16971 · Cited by 1,477
Flagged first, then by citations
Research works printed but not linked: 3
- N. Margolus, 1996, PhysComp96, Proceedings of the Fourth Workshop on Physics and Computation,
- N. Margolus, 1998, Physica (Amsterdam), 120D, 188
- D. G. Cory, PhysComp96, Proceedings of the Fourth Workshop on Physics and Computation
Cited by
Sorted by citations
A variational eigenvalue solver on a photonic quantum processor
Peruzzo, A., McClean, J., Shadbolt, P., Yung, M.-H., Zhou, X.-Q., Love, P. J., Aspuru-Guzik, A., & O’Brien, J. L. (2014) · Nature Communications · doi:10.1038/ncomms5213 · Cited by 4,552
Quantum-Enhanced Measurements: Beating the Standard Quantum Limit
Giovannetti, V., Lloyd, S., & Maccone, L. (2004) · Science · doi:10.1126/science.1104149 · Cited by 3,160
Self-citationThe World’s Technological Capacity to Store, Communicate, and Compute Information
Hilbert, M., & López, P. (2011) · Science · doi:10.1126/science.1200970 · Cited by 1,643
Complexity, action, and black holes
Brown, A. R., Roberts, D. A., Susskind, L., Swingle, B. G., & Zhao, Y. (2016) · Physical review. D/Physical review. D. · doi:10.1103/physrevd.93.086006 · Cited by 661
Quantum Speed Limits in Open System Dynamics
del Campo, A., Egusquiza, I. L., Plenio, M. B., & Huelga, S. F. (2013) · Physical Review Letters · doi:10.1103/physrevlett.110.050403 · Cited by 493
Metadata
- Authors
- Lloyd, S.
- Affiliations
- Massachusetts Institute of Technology (US)
- Corresponding author
- Lloyd, Seth
- ORCID
- Lloyd, Seth
- Venue
- Physical Review Letters
- Publisher
- American Physical Society (APS)
- Published
- 2002-05-24
- Volume
- 88
- Issue
- 23
- Pages
- 237901-237901
- ISSN
- 0031-9007 (ISSN-L)
- 1079-7114
- OpenAlex
- W1993466133
- Cited by
- 571
- References
- 35
- Citations by year
- 2026: 39 · 2025: 32 · 2024: 39 · 2023: 36 · 2022: 17 · 2021: 27 · 2020: 23 · 2019: 40 · 2018: 27 · 2017: 24 · 2016: 29 · 2015: 27 · 2014: 13 · 2013: 30 · 2012: 16
- FWCI
- 8.07
- Type
- journal article
- Language
- en
- Open access
- green
- arxiv.org
- Locations
- Physical Review Letters (publishedVersion)
- PubMed (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- CERN Document Server (European Organization for Nuclear Research) (submittedVersion)
- arXiv (Cornell University)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Cosmology and Gravitation Theories
- Physical Sciences › Computer Science › Computational Theory and Mathematics › Computability, Logic, AI Algorithms
- Physical Sciences › Physics and Astronomy › Nuclear and High Energy Physics › Black Holes and Theoretical Physics
- Keywords
- gravitational degrees of freedom
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review