David Tong: Strongly Coupled Systems

Strongly Coupled Systems


The European Research Council has funded a team of us to undertake a project entitled "Strongly Coupled Systems". In short, "strongly coupled systems" means stuff in physics that we don't understand very well. There are many famous examples, from QCD and the theory of quarks, to high temperature superconductors, to the big bang itself. In many cases, the problem is that the interactions between different particles become so intense that the mathematical tools that we use to describe them break down.

The purpose of this project is to develop new tools to attack these problems. Much of our focus is on holographic methods, but we are also using other techniques from supersymmetry, gravity and string theory to make progress in understanding these difficult questions.

Details of the team can be found here. A list of publications arising from the project can be found here. All publications are also available to free to download from the arXiv and conform to open access requirements.

The project runs from October 2011 to October 2017 and is funded under the European Union's Seventh Framework Programme (FP7/2007-2013), ERC Grant agreement STG 279943, "Strongly Coupled Systems".



Research Highlights

Here's a brief description of some of the things we've been working on. More details can be found in the list of publications.

Black Hole

Ohm's Law and Black Holes

Every kid in high school learns about Ohm's law: V=IR. But trying to compute the resistance, R, of a system from first principles is a very subtle affair. This is especially true if the system is strongly coupled. In a number of papers, Mike Blake, Aristos Donos and David Tong have developed methods to study the resistance of the horizon of a black hole in general relativity, as an example of a strongly interacting system. The results show that black holes share a surprising number of features with real world systems.

Higher Spin

Higher Spin Theories

The AdS/CFT correspondence -- more generally, the concept of holographic duality -- is widely used to study hard questions in quantum field theory using simpler techniques in gravity. But the reverse is also possible, which Eric Perlmutter has exploited to understand aspects of quantum gravity and the mechanism of the duality itself. He has recently developed new methods for computing measures of entanglement in conformal field theories, and matching these to geometric descriptions in gravity. He has also studied entanglement and black hole thermodynamics in theories of ``higher spin gravity,'' which are expected to model string theory at high energies.

Wormhole

Wormholes and Entanglement

An interesting recent development in quantum gravity is a conjectured slogan due to Maldacena and Susskind that reads "ER=EPR". Here ER stands for Einstein-Rosen: it refers to the wormhole that appears inside certain black hole solutions. Meanwhile EPR means Einstein, Podolsky and Rosen: it refers to the "spooky" entanglement that can occur between far separated particles in quantum mechanics. The slogan ER=EPR suggests that wormholes in spacetime are caused by quantum entanglement. Mariano Chernicoff explored this connection between wormholes and entanglement in the context of the AdS/CFT correspondence and found the necessary conditions for a wormhole to form.

A Skyrmion Lattice

Solitons and Impurities

Solitons are particles that emerge from the collective behaviour of underlying constituents. They arise in a number of different contexts, from condensed matter to particle physics to string theory. David Tong and Kenny Wong have developed a mathematical description of geometry underlying the scattering of BPS solitons off impurities. The ultimate goal of this research is to understand better the quantum mechanics of strongly coupled particles scattering off lattices of impurities.

Duality

A Duality Web

Often, two very different looking quantum field theories actually describe the same underlying physics. This is a phenomenon known as duality. Although well established in supersymmetric theories, it is much harder to demonstrate dualities in non-supersymmetric theories. In work with Andreas Karch, we found evidence for a web of dualities in d=2+1 dimensions. This work was motivated by a wonderfully diverse collection of ideas coming from high energy physics and condensed matter physics, including supersymmetric dualities, higher spin theories, the half-filled Landau level, and interacting topological insulators.



The Team

Mike

Mike Blake

Mike (2012-2016) is a PhD student at Cambridge and an affiliate member of the team. He has written papers on a number of topics, including baryon dynamics, Landau levels in the absence of quasi-particles and applciations of massive gravity to holography. After graduating, Mike got a prestigious research fellowship at Churchill College, Cambridge. He remains a key member of the team.

Mariano

Mariano Chernicoff

Mariano (2012-2013) joined the team after a PhD in Mexico University and postdocs at Barcelona and Cambridge. He is an expert in the use of holography to understand quark dynamics in the quark-gluon plasma. He also has an interest in the connection between Einstein-Rosen bridges and entanglement. He left the team to take up a faculty position at Universidad Nacional Autonoma de Mexico.

Aristos

Aristos Donos

Aristos (2013-2014) joined the team after a PhD in Brown University and postdoc positions at DESY and Imperial. He is one of the world leaders in holography, both in the construction of new supergravity backgrounds and in their uses to extract physical properties, such as conductivity, of strongly interacting matter. Aristos left the team to take up a faculty position in Durham University.

Nima

Nima Doroud

Nima (2014-2016) joined the team after a PhD in the Perimeter Institute. He is an expert in supersymmetric gauge theories in different dimensions.

Joao

Joao Laia

Joao (2011-2012) was a PhD student at Cambridge, joining the team for his final year. His interests are in holographic models of quantum matter. He found an interesting, and still poorly understood, phase of matter at finite density. After graduating, he moved on to take up a postdoc position in Crete.

Eric

Eric Perlmutter

Eric (2012-2014) joined us after completing his PhD in UCLA and a stint as a graudate fellow in KITP, Santa Barbara.. He is an expert in higher-spin theories, 2d CFTs and entanglement entropy. He left the team to take up a postdoc position in Princeton.

David

David Tong

David Tong (2011-2016) is the principal investigator. After postdoc positions in Mumbai, London, New York and Boston, he moved to Cambridge in 2004. He has worked on a wide variety of areas, from the mathematics of quantum geometry to inflationary cosmology. In recent years, his interest has been focussed on the dynamics of strongly interacting systems, with emphasis on holography and supersymmetric gauge theories.

Carl

Carl Turner

Carl (2013-2016) is a PhD at Cambridge and an affiliate member of the team. He is currently working on non-perturbative effects in quantum gravity and quantum field theory.

Kenny

Kenny Wong

Kenny (2011-2014) is PhD student at Cambridge, funded by the ERC grant. He has written papers on a wide variety of topics, including magnetic fields in holography, the fluctuation-dissipation theorem, topological insulators and supersymmetric solitons. After graduating, Kenny got a prestigious research fellowship at Gonville and Caius College, Cambridge. He remains a key member of the team.





Publications

  • [1] Magnetic Catalysis in AdS4
    Abstract   PDF
    Clas. Quantum Grav, Vol 29, 194003 (2012) arXiv:1110.5902 [hep-th].
    Stefano Bolognesi and David Tong

  • [2] Optical Conductivity with Holographic Lattices
    Abstract   PDF
    JHEP 1207 (2012) 168 arXiv:1204.0519 [hep-th].
    Gary Horowitz, Jorge Santos and David Tong

  • [3] A Gapless Hard Wall: Magnetic Catalysis in Bulk and Boundary
    Abstract   PDF
    JHEP 1207 (2012) 162 arXiv:1204.6029 [hep-th].
    Stefano Bolognesi, João Laia, David Tong and Kenny Wong

  • [4] Moduli Spaces of Cold Holographic Matter
    Abstract   PDF
    JHEP 1212 (2012) 039 arXiv:1208.3197 [hep-th].
    Martin Ammon, Kristan Jensen, Jeun-Young Kim, João Laia and Andy O'Bannon

  • [5] Holographic Dual of the Lowest Landau Level
    Abstract   PDF
    JHEP 1212 (2012) 039 arXiv:1208.5771 [hep-th].
    Mike Blake, Stefano Bolognesi, David Tong and Kenny Wong

  • [6] Further Evidence for Lattice-Induced Scaling
    Abstract   PDF
    JHEP 1211 (2012) 102 arXiv:1209.1098 [hep-th].
    Gary Horowitz, Jorge Santos and David Tong

  • [7] Fluctuation and Dissipation at a Quantum Critical Point
    Abstract   PDF
    Phys. Rev. Lett. 110, 061602 (2013), arXiv:1210.1580 [hep-th].
    David Tong and Kenny Wong

  • [8] Confinement in Anti-de Sitter Space
    Abstract   PDF
    JHEP 1302 076 (2013), arXiv:1210.5195 [hep-th].
    Ofer Aharony, Micha Berkooz, David Tong and Shimon Yankielowicz

  • [9] The Semiclassical Limit of W_N CFTs and Vasiliev Theory
    Abstract   PDF
    JHEP 1305 (2013) 007 arXiv:1210.8452 [hep-th].
    Eric Perlmutter, Tomas Prochazka and Joris Raeymaekers

  • [10] Matching Four-Point Functions in Higher Spin AdS_3/CFT_2
    Abstract   PDF
    JHEP 1305 (2013) 163 arXiv:1303.6113 [hep-th].
    Eliot Hijano, Per Kraus and Eric Perlmutter

  • [11] Gauge Dynamics and Topological Insulators
    Abstract   PDF
    JHEP 1309 025 (2013) arXiv:1305.2414 [hep-th].
    Benjamin Béri, David Tong and Kenny Wong

  • [12] Probing Higher Spin Black Holes from CFT
    Abstract   PDF
    JHEP 1310:045,2013 arXiv:1307.2221 [hep-th].
    Mathias Gaberdiel, Kewang Jin and Eric Perlmutter

  • [13] A Non-Abelian Vortex Lattice in Strongly Coupled Systems
    Abstract   PDF
    JHEP 1310 (2013) 148 arXiv:1307.7839 [hep-th].
    Kenny Wong

  • [14] A Universal Feature of CFT Renyi Entropy
    Abstract   PDF
    JHEP 1403 (2014) 117 arXiv:1308.1083 [hep-th].
    Eric Perlmutter

  • [15] Holographic EPR Pairs, Wormholes and Radiation
    Abstract   PDF
    JHEP 1310 (2013) 211 arXiv:1308.3695 [hep-th].
    Mariano Chernicoff, Alberto Guijosa and Juan Pedraza

  • [16] Universal Resistivity from Holographic Massive Gravity
    Abstract   PDF
    Phys. Rev. D 88, 106004 (2013) arXiv:1308.4970 [hep-th].
    Mike Blake and David Tong

  • [17] Vortices and Impurities
    Abstract   PDF
    JHEP 1401:090,2014 arXiv:1309.2644 [hep-th].
    David Tong and Kenny Wong

  • [18] Holographic Lattices Give the Graviton a Mass
    Abstract   PDF
    Phys. Rev. Lett. 112, 071602 (2014) arXiv:1310.3832.
    Mike Blake, David Tong and David Vegh

  • [19] Competing p-wave Orders
    Abstract   PDF
    Class.Quant.Grav. 31 (2014) 055007 arXiv:1312.5741 [hep-th].
    Aristos Donos, Jerome Gauntlett and Christiana Pantelidou

  • [20] Holographic Q-Lattices
    Abstract   PDF
    JHEP 1404 (2014) 040 arXiv:1311.3292 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [21] Comments on Renyi Entropy in AdS3/CFT2
    Abstract   PDF
    JHEP 1405 (2014) 052 arXiv:1312.5740 [hep-th].
    Eric Perlmutter

  • [22] Novel Metals and Insulators from Holography
    Abstract   PDF
    JHEP 1406 007 (2014) arXiv:1401.5077 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [23] Monopoles and Wilson Lines
    Abstract   PDF
    JHEP 1406 048 (2014) arXiv:1401.6167 [hep-th].
    David Tong and Kenny Wong

  • [24] The Holographic Dual of AdS3 x S3 x S3 x S1
    Abstract   PDF
    JHEP 1404 (2014) 193 arXiv:1402.5135 [hep-th].
    David Tong

  • [25] Flowing from AdS5 to AdS3 with T^(1,1)
    Abstract   PDF
    JHEP 1408 006 (2014) arXiv:1404.7133 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [26] Holographic Entanglement Entropy and Gravitational Anomalies
    Abstract   PDF
    JHEP 1407 114 (2014) arXiv:1405.2792 [hep-th].
    Alejandra Castro, Stephane Detournay, Nabil Iqbal and Eric Perlmutter

  • [27] Intersecting Branes, Domain Walls and Superpotentials in 3d Gauge Theories
    Abstract   PDF
    JHEP 1408 119 (2014) arXiv:1405.5226 [hep-th].
    Daniele Dorigoni and David Tong

  • [28] Quantum Critical Transport and the Hall Angle
    Abstract   PDF
    Phys. Rev. Lett. 114 021601 (2015) arXiv:1406.1659 [hep-th].
    Mike Blake and Aristos Donos

  • [29] Thermoelectric DC Conductivities from Black Hole Horizons
    Abstract   PDF
    JHEP 1411 081 (2014) arXiv:1406.4742 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [30] Holographic Metals and Insulators with Helical Symmetry
    Abstract   PDF
    JHEP 1409 038 (2014) arXiv:1406.6351 [hep-th].
    Aristos Donos, Blaise Gouteraux and Elias Kiritsis

  • [31] Renyi Entropy, Stationarity, and Entanglement of the Conformal Scalar
    Abstract   PDF
    JHEP 1503 075 (2015) arXiv:1407.7816 [hep-th].
    Jeongseog Lee, Aitor Lewkowycz, Eric Perlmutter and Ben Safdi

  • [32] Universality in the Geometric Dependence of Renyi Entropy
    Abstract   PDF
    JHEP 1501 080 (2015) arXiv:1407.8171 [hep-th].
    Aitor Lewkowycz and Eric Perlmutter

  • [33] Quantum Dynamics of Supergravity on R^3 x S^1
    Abstract   PDF
    JHEP 1412 142 (2014) arXiv:1408.3418 [hep-th].
    David Tong and Carl Turner

  • [34] The Thermoelectric Properties of Inhomogeneous Holographic Lattices
    Abstract   PDF
    JHEP 1501 035 (2015) arXiv:1409.6875 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [35] ADHM Revisited: Instantons and Wilson Lines
    Abstract   PDF
    Phys. Rev. D 91, 026007 (2015) arXiv:1410.8523 [hep-th].
    David Tong and Kenny Wong

  • [36] Holographic Charge Oscillations
    Abstract   PDF
    JHEP 1504 (2015) 019, arXiv:1412.2003 [hep-th].
    Mike Blake, Aristos Donos and David Tong

  • [37] Conformal Field Theories in d=4 with a Helical Twist
    Abstract   PDF
    Phys. Rev. D 91, 066003 (2015), arXiv:1412.3446 [hep-th].
    Aristos Donos, Jerome Gauntlett and Christiana Pantelidou

  • [38] Magnetothermoelectric Response from Holography
    Abstract   PDF
    JHEP 08 (2015) 124, arXiv:1502.03789 [hep-th].
    Mike Blake, Aristos Donos and Nakarin Lohitsiri

  • [39] Renyi Entropies, the Analytic Bootstrap, and 3D Quantum Gravity at Higher Genus
    Abstract   PDF
    JHEP 1507 (2015) 059 , arXiv:1503.07111 [hep-th].
    Matthew Headrick, Alexander Maloney, Eric Perlmutter, Ida Zadeh

  • [40] Momentum Relaxation from the Fluid/Gravity Correspondence
    Abstract   PDF
    JHEP 09 (2015) 010, arXiv:1505.06992 [hep-th].
    Mike Blake

  • [41] Magnetotransport from the fluid/gravity correspondence
    Abstract   PDF
    JHEP 1510 (2015) 078, arXiv:1507.04870 [hep-th].
    Mike Blake

  • [42] The Quantum Hall Effect in Supersymmetric Chern-Simons Theories
    Abstract  PDF
    Phys. Rev. B 92, 235125 (2015), arXiv:1508.00580 [hep-th].
    David Tong and Carl Turner

  • [43] Vortices and Monopoles in a Harmonic Trap
    Abstract  PDF
    JHEP 1512 (2015) 098, arXiv:1508.01207 [hep-th].
    David Tong and Carl Turner

  • [44] Review of Lattice Supersymmetry and Gauge-Gravity Duality
    Abstract  PDF
    Int.J.Mod.Phys.A30 (2015) 1530054, arXiv:1509.01440 [hep-th].
    Anosh Joseph

  • [45] Berry’s connection, Kahler geometry and the Nahm construction of monopoles
    Abstract  PDF
    JHEP 1512:147, 2015, arXiv:1511.01052 [hep-th].
    Kenny Wong

  • [46] On Superconformal Anyons
    Abstract  PDF
    JHEP 1601 (2016) 138, arXiv:1511.01491 [hep-th].
    Nima Doroud, David Tong and Carl Turner

  • [47] Spectral Sequences and Vacua in N=2 Gauged Linear Quantum Mechanics with Potentials
    Abstract  PDF
    JHEP 1603:150, 2016, arXiv:1511.05159 [hep-th].
    Kenny Wong

  • [48] Global Anomalies and Effective Field Theory
    Abstract  PDF
    JHEP 1605 (2016) 105, arXiv:1512.02607 [hep-th].
    Siavash Golkar and Savdeep Sethi

  • [49] Minimally Packed Phases in Holography
    Abstract  PDF
    JHEP 1603 (2016) 148, arXiv:1512.06861 [hep-th].
    Aristos Donos and Jerome Gauntlett

  • [50] A Higher-Spin Theory of the Magneto-Rotons
    Abstract  PDF
    Phys. Rev. Lett. 117, 216042 (2016), arXiv:1602.08499 [hep-th].
    Siavash Golkar, Dung Xuan Nguyen, Matthew Roberts and Dam Thanh Son

  • [51] Chasing the Cuprates with Dilatonic Dyons
    Abstract  PDF
    JHEP 06, 113 (2016), arXiv:1603.03029 [hep-th].
    Andrea Amoretti, Matteo Baggioli, Nicodemo Magnoli and Daniele Musso

  • [52] Universal Charge Diffusion and the Butterfly Effect
    Abstract  PDF
    Phys.Rev.Lett. 117, 091601 (2016) arXiv:1603.08510 [hep-th].
    Mike Blake

  • [53] A Matrix Model for Non-Abelian Quantum Hall States
    Abstract  PDF
    Phys. Rev. B94, 085114 (2016), arXiv:1603.09688 [cond-mat].
    Nick Dorey, David Tong and Carl Turner

  • [54] Universal Diffusion in Incoherent Black Holes
    Abstract  PDF
    Phys. Rev. D94, 086014, (2016), arXiv:1604.01754 [hep-th].
    Mike Blake

  • [55] A Euclidean Lattice Formulation of D=5 Maximally Supersymmetric Yang-Mills Theory
    Abstract  PDF
    JHEP 1606, 030 (2016), arXiv:1604.02707 [hep-lat].
    Anosh Joseph

  • [56] A Matrix Model for WZW
    Abstract  PDF
    JHEP 1608, 007 (2016), arXiv:1604.05711 [hep-th].
    Nick Dorey, David Tong and Carl Turner

  • [57] Gravity Duals of Boundary Cones
    Abstract  PDF
    JHEP 1609, 139 (2016), arXiv:1605.08588 [hep-th].
    Joan Camps

  • [58] Particle-Vortex Duality from 3d Bosonization
    Abstract  PDF
    Phys. Rev. X 6, 031043, arXiv:1606.01893 [hep-th].
    Andreas Karch and David Tong

  • [59] Non-Abelian 3d Bosonization and Quantum Hall States
    Abstract  PDF
    JHEP 1612 (2016) 067 , arXiv:1608.04732 [hep-th].
    Djordje Radicevic, David Tong and Carl Turner

  • [60] More Abelian Dualities in 2+1 Dimensions
    Abstract  PDF
    JHEP 1701 (2017) 017 , arXiv:1609.04012 [hep-th].
    Andreas Karch, Brandon Robinson and David Tong

  • [61] 5D Maximally Supersymmetric Yang-Mills on the Lattice
    Abstract  PDF
    Proceedings of Lattice16, arXiv:1610.03275 [hep-lat].
    Anosh Joseph

  • [62] The Conformal Spectrum of Non-Abelian Anyons
    Abstract  PDF
    arXiv:1611.05848 [hep-th].
    Nima Doroud, David Tong and Carl Turner

  • [63] Two-dimensional gauge dynamics and the topology of singular determinantal varieties
    Abstract  PDF
    JHEP 1703, 132 (2017) arXiv:1702.00730 [hep-th].
    Kenny Wong

  • [64] Quarter-BPS states in orbifold sigma models with ADE singularities
    Abstract  PDF
    JHEP 1706, 116 (2017), arXiv:1704.02926 [hep-th].
    Kenny Wong

  • [65] Line Operators in the Standard Model
    Abstract  PDF
    JHEP 1707, 104 (2017), arXiv:1705.01853 [hep-th].
    David Tong

  • [66] ADHM and the 4d Quantum Hall Effect
    Abstract  PDF
    arXiv:1710.09833 [hep-th].
    Alec Barns-Graham, Nick Dorey, Nakarin Lohitsiri, David Tong and Carl Turner

  • [67] Bosonization in Non-Relativistic CFTs
    Abstract  PDF
    arXiv:1712.07662 [hep-th].
    Carl Turner