# Dr Sanjaye Ramgoolam

## Reader in Theoretical Physics

Email: s.ramgoolam@qmul.ac.uk

Telephone: 020 7882 5799

Room Number: G. O. Jones Building, Room 609

## Profile

My research is in the areas of string theory, combinatorics and representation theory. My papers are available at Google Scholar

I am currently teaching Mathematical Techniques 4 (Year 3) and Advanced Quantum Field theory (Year 4)

## Teaching

Currently teaching :

- PHY6324 (Mathematical Techniques 4)
- SPA7001U/P (Advanced Quantum Field Theory)

Undergraduate Projects supervised :

- From classical strings to photons and gravtions
- Plasma Physics and Nuclear Fusion
- Dark Matter, dark energy and cosmology
- Entanglement and decoherence in quantum physics

Modules taught in the past :

- Electromagnetic theory (4th year MSci course)
- Quantum Mechanics and Symmetry (3rd year)
- Electromagnetism for pre-medical (at Brown)
- Quantum Physics (1st year)

## Research

### Research Interests:

### String theory, representation theory, combinatorics

My recent work has largely been in gauge-string duality, in particular the AdS/CFT correspondence, which relates 4-dimensional quantum field theory (QFT) to 10-dimensional string theory. I have developed a mathematical framework based on symmetric groups, Brauer algebras, representation theory, combinatorics, in understanding the map between states in the QFT and states of strings, branes and geometries in the 10 dimensions. A recent theme emerging from these investigations is the role of two-dimensional topological field theories (TFT2) as a structure which captures both the combinatorics and spacetime dependences of correlators in four-dimensional theories. I have also developed simple mathematical models of gauge-string duality in low dimensions, e.g deriving the counting of strings wrapping the two-dimensional sphere from matrix models, which can be viewed as zero dimensional QFT. Some of the mathematical techniques have also been applied to find new counting results for Feynman diagrams in QFT, including the simplest ones : scalar field theory and quantum electrodynamics (QED, which describes photons and electrons).

A very recent interdisciplinary direction (initiated in a collaboration with D. Kartsaklis and M. Sadrzadeh) has been to develop matrix theory techniques to give a framework for analyzing matrix data in computational linguistics. This is a video of the talk I gave at the ``Quantum Physics and Logic'' conference organized by the Oxford Quantum Group.

A complete list of my papers can be accessed at Inspire-HEP-database or Google scholar (Following standard practice in theoretical particle physics, author lists are all alphabetical)

Selected papers organised by theme (although some lie at interfaces of these themes** **

**CFT4 as TFT2**

1. CFT4 as SO(4,2)-invariant TFT2

3. Free quantum fields in 4D and Calabi Yau spaces

#### AdS/CFT, giant graviton branes, correlators of gauge invariant operators

Half-BPS case (related to one-matrix combinatorics)

Eighth-BPS case (related to multi-matrix combinatorics)

- Diagonal multi-matrix correlators and BPS operators in N=4 SYM.
- From counting to construction of BPS states in N=4 SYM.
- Branes, anti-branes and brauer algebras in gauge-gravity duality.

#### Non-BPS and Integrability

#### Fuzzy geometry

- On spherical harmonics for fuzzy spheres in diverse dimensions.
- The Fuzzy S2 structure of M2-M5 systems in ABJM membrane theories.
- Noncommutative gravity from the AdS / CFT correspondence.
- Quantum states to brane geometries via fuzzy moduli spaces of giant gravitons.

#### Mathematical models of gauge-string duality

- Large N 2-D Yang-Mills theory and topological string theory
- From Matrix Models and Quantum Fields to Hurwitz Space and the absolute Galois Group.
- Strings from Feynman Graph counting : without large N.

#### Supersymmetric Gauge theories

#### Matrix Model of M-theory

### Examples of research funding:

Current and recent grants :

- Visiting Professorship, Wits University South Africa
- Science and Technology Facilities Council, (£703,989). Brandhuber, Berman, Buican, Figueras, Ramgoolam, Russo, Shigemori, Spence, Thomas, Travaglini, White. Consolidated grant String theory, gauge theory and duality (2017-2020)
- Science and Technology Facilities Council, (£632,431). Brandhuber, Berman, Ramgoolam, Russo, Spence, Thomas, Travaglini, Wecht. Consolidated grant String theory, gauge theory and duality (2011-2014)
- Science and Technology Facilities Council, (£1,431,413). Spence Berman, Brandhuber, Ramgoolam, Russo, Thomas, Travaglini. Rolling grant String theory, gauge theory and duality (2008-2013)
- Particle Physics and Astronomy Research Council: Spence , Berman, Brandhuber, Ramgoolam, Thomas. Rolling grant String theory, gauge theory and gravity (2006-2010), (£249,800.)
- STFC (PPARC) Advanced Fellowship, 2003-2008 (£220,000)
- Scientist in charge for Marie Cure Outgoing Fellowship ( MOIF-CT-2006-038381) held by Diego Rodriguez Gomez at QMUL and Princeton.
- Royal Society International exchange grants with South Africa and Cyprus.

## Publications

The complete and up-to-date list of my publications is available at the Inspire-Hep database and at Google Scholar

A description of some my research organized according to some general themes is under the Research tab.

## 2016

**Flavour singlets in gauge theory as permutations**

Kimura Y, Ramgoolam S, Suzuki R*Journal of High Energy Physics, *Volume 2016, issue 12, 28th December 2016.

DOI: 10.1007/JHEP12(2016)142

**Gauge invariants and correlators in flavoured quiver gauge theories**

Mattioli P, Ramgoolam S*Nuclear Physics B, *Volume 911, page 638, 1st October 2016.

DOI: 10.1016/j.nuclphysb.2016.08.021

**Consistency and derangements in brane tilings**

Hanany A, Jejjala V, Ramgoolam S et al.*Journal of Physics A: Mathematical and Theoretical, *Volume 49, issue 35, page 355401, 2nd September 2016.

DOI: 10.1088/1751-8113/49/35/355401

**Interactions as intertwiners in 4D QFT**

de Mello Koch R, Ramgoolam S*Journal of High Energy Physics, *Volume 2016, issue 3, 23rd March 2016.

DOI: 10.1007/JHEP03(2016)165

**Permutation Centralizer Algebras and Multi-Matrix Invariants**

Mattioli P, Ramgoolam S*Physical Review D - Particles, Fields, Gravitation, and Cosmology, *21st March 2016.

DOI: 10.1103/PhysRevD.93.065040

## 2015

**The geometry of the light-cone cell decomposition of moduli space**

Garner D, Ramgoolam S*JOURNAL OF MATHEMATICAL PHYSICS, *Volume 56, issue 11, 1st November 2015.

DOI: 10.1063/1.4934365

**Permutation combinatorics of worldsheet moduli space**

Freidel L, Garner D, Ramgoolam S*PHYSICAL REVIEW D, *Volume 91, issue 12, 9th June 2015.

DOI: 10.1103/PhysRevD.91.126001

**Quivers, words and fundamentals**

Mattioli P, Ramgoolam S*Journal of High Energy Physics, *Volume 2015, issue 3, 21st February 2015.

DOI: 10.1007/JHEP03(2015)105

## 2013

**Quivers as Calculators: Counting, Correlators and Riemann Surfaces**

Pasukonis J, Ramgoolam S*The Journal of High Energy Physics, *Volume 94, issue 04, 9th January 2013.

DOI: 10.1007/JHEP04(2013)094

## 2012

**INVARIANTS OF TORIC SEIBERG DUALITY**

Hanany A, He Y-H, Jejjala V et al.*INTERNATIONAL JOURNAL OF MODERN PHYSICS A, *Volume 27, issue 1, 10th January 2012.

DOI: 10.1142/S0217751X12500029

## 2011

**Calabi-Yau orbifolds and torus coverings**

Hanany A, Jejjala V, Ramgoolam S et al.*JOURNAL OF HIGH ENERGY PHYSICS, *issue 9, 1st September 2011.

DOI: 10.1007/JHEP09(2011)116

## 2009

**The fuzzy S-2 structure of M2-M5 systems in ABJM membrane theories**

Nastase H, Papageorgakis C, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2009, issue 5, 1st May 2009.

DOI: 10.1088/1126-6708/2009/05/123

**Diagonal free field matrix correlators, global symmetries and giant gravitons**

Brown TW, Heslop PJ, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2009, issue 4, 1st April 2009.

DOI: 10.1088/1126-6708/2009/04/089

## 2008

**Enhanced symmetries of gauge theory and resolving the spectrum of local operators**

Kimura Y, Ramgoolam S*PHYS REV D, *Volume 78, issue 12, 1st December 2008.

DOI: 10.1103/PhysRevD.78.126003

**Holomorphic maps and the complete 1/N expansion of 2D SU(N) Yang-Mills**

Kimura Y, Ramgoolam S*J HIGH ENERGY PHYS, *issue 6, 1st June 2008.

DOI: 10.1088/1126-6708/2008/06/015

**Diagonal multi-matrix correlators and BPS operators in N=4 SYM**

Brown TW, Heslop PJ, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2008, issue 2, 1st February 2008.

DOI: 10.1088/1126-6708/2008/02/030

**Schur-Weyl duality as an instrument of gauge-string duality**

Ramgoolam S*TEN YEARS OF ADS/CFT, *Volume 1031, page 255, 1st January 2008.

DOI: 10.1063/1.2972012

## 2007

**Large N expansion of q-deformed two-dimensional Yang-Mills theory and Hecke algebras**

de Haro S, Ramgoolam S, Torrielli A*COMMUN MATH PHYS, *Volume 273, issue 2, page 317, 1st July 2007.

DOI: 10.1007/s00220-007-0232-4

**Correlators, probabilities and topologies in N=4 SYM**

Brown T, Ramgoolam S, Koch RD et al.*J HIGH ENERGY PHYS, *issue 3, 1st March 2007.

DOI: 10.1088/1126-6708/2007/03/072

## 2006

**On time-dependent collapsing branes and fuzzy odd-dimensional spheres**

Papageorgakis C, Ramgoolam S*INT J MOD PHYS A, *Volume 21, issue 30, page 6055, 10th December 2006.

DOI: 10.1142/S0217751X06034161

**Finite N effects on the collapse of fuzzy spheres**

McNamara S, Papageorgakis C, Ramgoolam S et al.*J HIGH ENERGY PHYS, *issue 5, 1st May 2006.

DOI: 10.1088/1126-6708/2006/05/060

**Noncommutative geometry, quantum effects and DBI-scaling in the collapse of D0-D2 bound states**

Papageorgakis C, Ramgoolam S, Toumbas N*J HIGH ENERGY PHYS, *issue 1, 1st January 2006.

DOI: 10.1088/1126-6708/2006/01/030

## 2005

**On exponential corrections to the 1/N expansion in two-dimensional Yang Mills**

Koch RD, Jevicki A, Ramgoolam S*J HIGH ENERGY PHYS, *issue 8, 1st August 2005.

DOI: 10.1088/1126-6708/2005/08/077

**Non-associative gauge theory and higher spin interactions**

de Medeiros P, Ramgoolam S*J HIGH ENERGY PHYS, *issue 3, 1st March 2005.

DOI: 10.1088/1126-6708/2005/03/072

**Large-small dualities between periodic collapsing/expanding branes and brane funnels**

RAMGOOLAM SK, Papageorgakis C*JHEP, *1st January 2005.

DOI: 10.1016/j.nuclphysb.2005.09.044

## 2004

**Resolving brane collapse with 1/N corrections in non-Abelian DBI**

Ramgoolam S, Spence B, Thomas S*NUCL PHYS B, *Volume 703, issue 1-2, page 236, 20th December 2004.

DOI: 10.1016/j.nuclphysb.2004.10.012

**Towards gauge theory for a class of commutative and non-associative fuzzy spaces**

Ramgoolam S*J HIGH ENERGY PHYS, *issue 3, 1st March 2004.

DOI: 10.1088/1126-6708/2004/03/034

**Strings on plane waves, super-Yang-Mills in four dimensions, quantum groups at roots of one**

Corley S, Ramgoolam S*NUCL PHYS B, *Volume 676, issue 1-2, page 99, 5th January 2004.

DOI: 10.1016/j.nuclphysb.2003.10.017

## 2003

**Massive IIA string theory and Matrix theory compactification**

Lowe DA, Nastase H, Ramgoolam S*NUCL PHYS B, *Volume 667, issue 1-2, page 55, 8th September 2003.

DOI: 10.1016/S0550-3213(03)00547-9

## 2002

**Finite factorization equations and sum rules for BPS correlators in N=4 SYM theory**

Corley S, Ramgoolam S*NUCL PHYS B, *Volume 641, issue 1-2, page 131, 7th October 2002.

DOI: 10.1016/S0550-3213(02)00573-4

**Higher dimensional geometries related to fuzzy odd-dimensional spheres**

Ramgoolam S*J HIGH ENERGY PHYS, *issue 10, 1st October 2002.

DOI: 10.1088/1126-6708/2002/10/064

**Higher-dimensional geometries from matrix brane constructions**

Ho PM, Ramgoolam S*NUCL PHYS B, *Volume 627, issue 1-2, page 266, 15th April 2002.

DOI: 10.1016/S0550-3213(02)00072-X

## 2001

**Einstein-Hilbert on the brane**

Corley S, Lowe DA, Ramgoolam S*JOURNAL OF THE KOREAN PHYSICAL SOCIETY, *Volume 39, page S566, 1st December 2001.

**On spherical harmonics for fuzzy spheres in diverse dimensions**

Ramgoolam S*NUCL PHYS B, *Volume 610, issue 3, page 461, 10th September 2001.

DOI: 10.1016/S0550-3213(01)00315-7

**Einstein-Hilbert action on the brane for the bulk graviton**

Corley S, Lowe DA, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2001, issue 7, 1st July 2001.

DOI: 10.1088/1126-6708/2001/07/030

**Exact correlators of giant gravitons from dual N=4 SYM theory**

RAMGOOLAM SK, Jevicki A, Corley S*ADVANCES IN THEORETICAL AND MATHEMATICAL PHYSICS, *Volume 5, issue 4, page 809, 1st July 2001.

DOI: 10.4310/ATMP.2001.v5.n4.a6

**Projector equivalences in K theory and families of non-commutative solitons**

Corley S, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2001, issue 3, 1st March 2001.

DOI: 10.1088/1126-6708/2001/03/037

**On the polarization of unstable D0-branes into non-commutative odd spheres**

Guralnik Z, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2001, issue 2, 1st February 2001.

DOI: 10.1088/1126-6708/2001/02/032

## 2000

**Non-commutative spheres and the AdS/CFT correspondence**

Jevicki A, Mihailescu M, Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2000, issue 10, 1st October 2000.

DOI: 10.1088/1126-6708/2000/10/008

**A remark on T-duality and quantum volumes of zero-brane moduli spaces**

Ramgoolam S*J HIGH ENERGY PHYS, *Volume 2000, issue 9, 1st September 2000.

DOI: 10.1088/1126-6708/2000/09/026

**A double coset ansatz for integrability in AdS/CFT**

Koch RDM, Ramgoolam S

DOI: 10.1007/JHEP06(2012)083

**Branes, Anti-Branes and Brauer Algebras in Gauge-Gravity duality**

Kimura Y, Ramgoolam S*JHEP, *Volume 0711, page 078, DOI: 10.1088/1126-6708/2007/11/078

**Branes, Fluxes and Duality in M(atrix)-Theory**

Ganor OJ, Ramgoolam S, IV WT*Nucl.Phys.B, *Volume 492, page 191, DOI: 10.1016/S0550-3213(97)00100-4

**CFT4 as SO(4,2)-invariant TFT2**

Koch RDM, Ramgoolam S*Nuclear Physics, Section B, *DOI: 10.1016/j.nuclphysb.2014.11.013

**Calabi-Yau Orbifolds and Torus Coverings**

Hanany A, Jejjala V, Ramgoolam S et al.*JHEP, *Volume 1109, page 116, DOI: 10.1007/JHEP09(2011)116

**Chiral Ring Generating Functions & Branches of Moduli Space**

McGrane J, Ramgoolam S, Wecht B

**Comment on Two Dimensional O(N) and Sp(N) Yang Mills Theories as String Theories**

Ramgoolam S*Nucl.Phys. B, *Volume 418, page 30, DOI: 10.1016/0550-3213(94)90237-2

**Counting Tensor Model Observables and Branched Covers of the 2-Sphere**

Geloun JB, Ramgoolam S

**D-Branes and Physical States**

Ramgoolam S, Thorlacius L*Nucl.Phys. B, *Volume 483, page 248, DOI: 10.1016/S0550-3213(96)00475-0

**Duality and Combinatorics of Long Strings in ADS3**

Mihailescu M, Ramgoolam S*Nucl.Phys. B, *Volume 587, page 179, DOI: 10.1016/S0550-3213(00)00444-2

**Exact S-Matrix for 2D String Theory**

Moore G, Plesser MR, Ramgoolam S*Nucl.Phys.B, *Volume 377, page 143, DOI: 10.1016/0550-3213(92)90020-C

**Free particles from Brauer algebras in complex matrix models**

Kimura Y, Ramgoolam S, Turton D*JHEP, *Volume 1005, page 052, DOI: 10.1007/JHEP05(2010)052

**From 0-Branes to Torons**

Guralnik Z, Ramgoolam S*Nucl.Phys. B, *Volume 521, page 129, DOI: 10.1016/S0550-3213(98)00070-4

**From Matrix Models and quantum fields to Hurwitz space and the absolute Galois group**

Koch RDM, Ramgoolam S

**From counting to construction of BPS states in N=4 SYM**

Pasukonis J, Ramgoolam S*JHEP, *Volume 1102, page 078, DOI: 10.1007/JHEP02(2011)078

**Gravity from CFT on $S^N(X)$ CFT: Symmetries and Interactions**

Jevicki A, Mihailescu M, Ramgoolam S*Nucl.Phys. B, *Volume 577, page 47, DOI: 10.1016/S0550-3213(00)00147-4

**Hidden classical symmetry in quantum spaces at roots of unity : From q-sphere to fuzzy sphere**

Jevicki A, Mihailescu M, Ramgoolam S

**Higher Loop Effects in M(atrix) Orbifolds**

Ganor OJ, Gopakumar R, Ramgoolam S*Nucl.Phys. B, *Volume 511, page 243, DOI: 10.1016/S0550-3213(97)00654-8

**Highest Weight Generating functions for hyperKahler T*(G/H) spaces**

Hanany A, Ramgoolam S, Rodriguez-Gomez D*Journal of High Energy Physics, *DOI: 10.1007/JHEP10(2016)021

**Holographic Hierarchy in the Gaussian Matrix Model via the Fuzzy Sphere**

Garner D, Ramgoolam S*Nucl.Phys. B, *Volume 875, page 244, DOI: 10.1016/j.nuclphysb.2013.06.020

**Interactions as intertwiners in 4D QFT**

Koch RDM, Ramgoolam S*Journal of High Energy Physics, *DOI: 10.1007/JHEP03(2016)165

**Invariants of Toric Seiberg Duality**

Hanany A, He Y-H, Jejjala V et al.

DOI: 10.1142/S0217751X12500029

**Large N 2D Yang-Mills Theory and Topological String Theory**

Cordes S, Moore G, Ramgoolam S*Commun.Math.Phys., *Volume 185, page 543, DOI: 10.1007/s002200050102

**Lectures on 2D Yang-Mills Theory, Equivariant Cohomology and Topological Field Theories**

Cordes S, Moore G, Ramgoolam S*Nucl.Phys.Proc.Suppl., *Volume 41, page 184, DOI: 10.1016/0920-5632(95)00434-B

**Linguistic Matrix Theory**

Kartsaklis D, Ramgoolam S, Sadrzadeh M

**New Modular Hopf Algebras related to rational $k$ $\widehat {sl(2)}$**

Ramgoolam S

**Non commutative gravity from the ADS/CFT correspondence**

Jevicki A, Ramgoolam S*JHEP, *Volume 9904, page 032, DOI: 10.1088/1126-6708/1999/04/032

**On Matrix Models of M5-branes**

Brodie J, Ramgoolam S*Nucl.Phys. B, *Volume 521, page 139, DOI: 10.1016/S0550-3213(98)00071-6

**On the refined counting of graphs on surfaces**

Koch RDM, Ramgoolam S, Wen C

DOI: 10.1016/j.nuclphysb.2013.01.023

**Permutation centralizer algebras and multimatrix invariants**

RAMGOOLAM SK*Physical Review D - Particles, Fields, Gravitation, and Cosmology, *DOI: 10.1103/PhysRevD.93.065040

**Permutations and the combinatorics of gauge invariants for general N**

Ramgoolam S*Proceedings of Science, *

**Quantum Spacetimes and Finite N Effects in 4D Super Yang-Mills Theories**

Ho P-M, Ramgoolam S, Tatar R*Nucl.Phys. B, *Volume 573, page 364, DOI: 10.1016/S0550-3213(99)00819-6

**Quantum states to brane geometries via fuzzy moduli spaces of giant gravitons**

Pasukonis J, Ramgoolam S

DOI: 10.1007/JHEP04(2012)077

**Scattering of zero branes off elementary strings in Matrix Theory**

Gopakumar R, Ramgoolam S*Nucl.Phys. B, *Volume 514, page 177, DOI: 10.1016/S0550-3213(97)00726-8

**Some properties of unstable monopoles in Super-QCD**

Barbon JLF, Ramgoolam S*Phys.Rev. D, *Volume 55, page 1013, DOI: 10.1103/PhysRevD.55.1013

**Strings from Feynman Graph counting : without large N**

Koch RDM, Ramgoolam S

DOI: 10.1103/PhysRevD.85.026007

**Stringy Spacetime Uncertainty as an Alternative to Inflation**

Gu J-A, Ho P-M, Ramgoolam S

**The Beta Ansatz: A Tale of Two Complex Structures**

Hanany A, He Y-H, Jejjala V et al.*JHEP, *Volume 1106, page 056, DOI: 10.1007/JHEP06(2011)056

**Thresholds of Large N Factorization in CFT4 : Exploring bulk spacetime in AdS5**

Garner D, Ramgoolam S, Wen C*Journal of High Energy Physics, *DOI: 10.1007/JHEP11(2014)076

**Toric CFTs, Permutation Triples, and Belyi Pairs**

Jejjala V, Ramgoolam S, Rodriguez-Gomez D*JHEP, *Volume 1103, page 065, DOI: 10.1007/JHEP03(2011)065

**Torons and D-Brane Bound States**

Guralnik Z, Ramgoolam S*Nucl.Phys. B, *Volume 499, page 241, DOI: 10.1016/S0550-3213(97)00286-1

**Wilson Loops in 2D Yang Mills: Euler characters and Loop equations**

Ramgoolam S*Int.J.Mod.Phys. A, *Volume 11, page 3885, DOI: 10.1142/S0217751X96001838

**Zero-Branes on a Compact Orbifold**

Ramgoolam S, Waldram D*JHEP, *Volume 9807, page 009, DOI: 10.1088/1126-6708/1998/07/009

## PhD Supervision

### PhDs/Postdocs

PhD students supervised :

- Costis Papageorgakis
- Tom Brown
- David Turton
- Jurgis Pasukonis
- David Garner
- Paolo Mattioli
- Christopher Lewis-Brown (Current)

Recent post-doctoral collaborators at QMUL :

- Ali Zahabi
- Diego Rodriguez Gomez
- Vishnu Jejjala
- Yusuke Kimura
- Paul Heslop
- Congkao Wen

This is not an exhaustive list and I would be happy to discuss other project possibilities.

## Project Title

### Combinatorics and Representation Theory in Gauge-String in CFT and ADS/CFT

Symmetric groups and their group algebras, along with concepts in representation theory including Schur-Weyl duality, have been applied to the study of half-BPS states in N=4 SYM theory, in particular to clarify the holographic map of the AdS/CFT correspondence. **For full details click **here

## Public Engagement

### Some research presentations

- Permutation centralizer?algebras, polynomial invariants and supersymmetric states [PDF 1,066KB](talk at conference on representation theory and physics, Leeds, July 2016)
- BPS states, permutations and information (talk at YITP Kyoto programme on string theory, condensed matter physics and quantum information, June 2016)
- Quantum Field thories (QFTs), quivers and word combinatorics [PDF 4,825KB] (talk at theory group, computer science, EECS, QMUL, Oct. 21, 2015)
- CFT4?(4D?conformal QFT) as TFT2( 2D topological field theory) [PDF 4,438KB] (talk at school of Maths, QMUL, Mar 2, 2015)
- Quiver gauge theory and TFT2s (2d topological field theories) [PDF 8,116KB] (talk at Quantum integrability workshop, Surrey, 08/2014)
- Quantum states to brane geometries via fuzzy moduli space [PDF 517KB] (talk at Oxford Maths Institute, 02/12)
- Permutations, strings and Feynman Graphs [PDF 631KB] ( talk at City Maths Dept, 11/2011)
- Strings, Permutations and Quantum Fields [PDF 476KB] (talk at Corfu2011 workshop on non-commutatve field theory and gravity)
- Symmetric groups and local operators in gauge theory [PDF 499KB] (talk at Lisbon 2011)
- From numbers to strings and branes [PDF 83KB] (talk at Galileo Galilei Institute 2011)
- Feynman Diagrams and Absolute Galois group [PDF 293KB] (talk at B(A)MC 2010)
- Matrix Models, Hurwitz spaces Galois Group [PDF 667KB](talk in Southampton Pure Maths group)
- Fuzzy geometry of membranes in M-theory [PDF 314KB] (talk at Imperial)

### A short review article:

- Schur-Weyl duality and Gauge-string duality (Talk given at "Ten years of AdS/CFT in Argentina,2008)

### Outreach

Some popular talks :

- Duality and Emergence in String theory, talk at the Mauritius Diaspora Conference 2018
- Symmetries and Surprises in String Theory (Talk for Psi Star QMUL, December 2013)
- What is String Theory ? (talk at Bryanston School, April 2012)
- Strings and hidden geometries (talk at Inauguration of School of Phys and Astro 2012)
- String Theory and Hidden dimensions of spacetime (talk for Waltham Forest Physics masterclass)
- From force and matter to strings( talk at Highgate school, 2003)
- Strings in the quantum world ( talk at Oxford, 2009 )
- Duality and the nature of quantum space-time : ( talk at Oxford,Jan 2009 )
- Space and Time, Light and Gravity in String Theory ( talk at PPARC 2006)