João Faria Martins

Mathematics Department

Faculty of Sciences and Technology

Universidade Nova de Lisboa.

Quinta da Torre
2829-516 Caparica
Portugal

  jn.martins -at- fct dot unl dot pt


NOT UP-TO-DATE: I am officially on-leave.
This is my current webpage.


I am an assistant professor at the Mathematics Department of the Faculty of Sciences and Technology of Universidade Nova de Lisboa, in Lisbon, Portugal.  

I am also an Executive Committee member of the research unit CMA (Centro de Matemática e Aplicações da Universidade Nova de Lisboa), and an official collaborator at the research unit Grupo de Física Matemática da Universidade de Lisboa.

Previously I was an assistant researcher at the Centro de Matemática da Universidade do Porto, in Oporto,  Portugal. I was offered that position under the programme Ciência 2007 of Fundação para a Ciência e Tecnologia.


Before that I was a postdoctoral fellow at the Mathematics Department of Instituto Superior Técnico, in Lisbon, Portugal,  affiliated with the  Center for Mathematical Analysis, Geometry, and Dynamical Systems, and financially supported by Fundação para a Ciência e Tecnologia.

I did my PhD at the School of Mathematical Sciences of  Nottingham University. My supervisor was John W. Barrett.

Here are my pages at Mathematical Reviews, scholar.google; inspire (hep-th); ORCID; ResearcherID.

Official page at the Mathematics Department of the Faculty of Sciences and Technology of Universidade Nova de Lisboa.  


Since in 2010, I have been involved in the organisation of the summer “Matnova”. This is a summer school in Mathematics conceived for high achieving secondary school students, with the aim of encouraging excellent students to go on to study for a degree in Mathematics. Each edition (of 5 days) revolves around seminars and courses. You can see the individual pages of each edition in Matnova2010 , Matnova2011 , Matnova2012 , Matnova2013 , Matnova2014 , Matnova2015 . We welcomed 83 participants in the 2015 edition.

   
Research Interests:
 

-Algebraic and Geometric Topology in dimensions 3 and 4.
-Higher dimensional category theory.
-Applications to condensed matter Physics and quantum computing.
-Quantum groups and low dimensional topology.
-Algebraic models for homotopy types.
-Differential geometry (higher Lie and gauge theory).
-Mathematical aspects of Chern-Simons Theory and BF-theory.
   

Preprints (comments are very welcome):


-Categorifying the $sl(2,C)$ Knizhnik-Zamolodchikov Connection via an Infinitesimal 2-Yang-Baxter Operator in the String Lie-2-Algebra, with Lucio Simone Cirio.



Publications:

Crossed modules of Hopf algebras and of associative algebras and two-dimensional holonomy. To appear in Journal of Geometry and Physics. Preliminary version.

Pointed Homotopy of Maps Between 2-Crossed Modules of Commutative Algebras, with İ.İlker Akça and Kadir Emir. To appear in Homology, Homotopy and Applications. Preliminary version.

Link invariants from finite categorical groups, with Roger Picken. To appear in Homology, Homotopy and Applications. This is a very reduced version of: Link invariants from finite categorical groups and braided crossed modules.

-Infinitesimal 2-braidings and differential crossed modules, with Lucio Cirio. Advances in Mathematics, Volume 277, 4 June 2015, Pages 426–491. Preliminary version.

-Pointed homotopy and pointed lax homotopy of 2-crossed module maps, with Björn Gohla, Advances in Mathematics Volume 248, 25 November 2013, Pages 986–1049. Preliminary version. Very preliminary version.

-Spin Foam State Sums and Chern-Simons Theory,  with 
 Aleksandar Miković . Chern-Simons gauge theory: 20 years after, 277–284, AMS/IP Stud. Adv. Math., 50, Amer. Math. Soc., Providence, RI, 2011. Preliminary version.

-Categorifying the Knizhnik–Zamolodchikov connection, with Lucio Simone Cirio, Differential Geometry and its Applications, Volume 30, Issue 3, June 2012, Pages 238–261. Preliminary version.

-Four-Dimensional Spin Foam Perturbation Theory,  with  Aleksandar Miković . Symmetry, Integrability and Geometry: Methods and Applications (SIGMA). 7 (2011), 094, 22 pages.

-The fundamental 2-crossed complex of a reduced CW-complex. Homology, Homotopy and Applications, Vol. 13 (2011), No. 2, pp.129-157.

-Lie crossed modules and gauge-invariant actions for 2-BF theories,  with  Aleksandar Miković. Advances in Theoretical and Mathematical Physics, Volume 15, Number 4 (August 2011) p.1059-1084. Preliminary version

-Surface Holonomy for Non-Abelian 2-Bundles via Double Groupoids, with Roger Picken. Advances in Mathematics Volume 226, Issue 4, 1 March 2011, Pages 3309-3366. Preliminary version. Very preliminary version.

-The fundamental Gray 3-groupoid of a smooth manifold and local 3-dimensional holonomy based on a 2-crossed module, with Roger Picken. Differential Geometry and its Applications Volume 29, Issue 2, March 2011, Pages 179-206. Preliminary version. Very preliminary version.

-On Two-Dimensional Holonomy, with Roger Picken. Transactions of the American Mathematical Society, 362 (2010), 5657-5695.

-Spin Foam Perturbation Theory for Three-Dimensional Quantum Gravity,  with  Aleksandar Miković . Communications in Mathematical Physics. Volume 288, Number 2 / June, 2009.

-The Fundamental Crossed Module of the Complement of a Knotted Surface.  Transactions of the American Mathematical Society.   361 (2009), 4593-4630.

-Invariants of Welded Virtual Knots Via Crossed Module Invariants of Knotted Surfaces, with Louis H. Kauffman.   Compositio Mathematica. Volume 144, Issue 04, July 2008, pp 1046-1080.

-Invariants of Spin Networks Embedded  in Three-Manifolds,  with  Aleksandar Miković.   Communications in Mathematical Physics, Volume  279, Number 2/ Abril 2008, pages 381-399.

-Observables in the Turaev-Viro and Crane-Yetter models
, with John W. Barrett and J. Manuel Garcia Islas.   Journal of Mathematical Physics, 48, 093508 (2007) (18 pages).

-On Yetter's Invariant and an Extension of the Dijkgraaf-Witten Invariant to Categorical Groups, with Timothy Porter.   Theory and Application of Categories, Vol. 18, 2007, No. 4, pp 118-150.

-On the Homotopy Type and the Fundamental Crossed Complex of the Skeletal Filtration of a CW-Complex. Homology Homotopy and Applications, Vol. 9 (2007), No. 1, pp.295-329.

-Categorical Groups, Knots and Knotted Surfaces, J. Knot Theory Ramifications 16 (2007), no 9, 1181-1217.    



PhD Thesis:


-Quantum Topology and the Lorentz Group.

   
Thesis related publications


-Knot Theory with the Lorentz Group FUNDAMENTA MATHEMATICAE 188 (2005), 59-93. (Special volume based on papers submitted by the participants of the Second International Conference “Knots in Poland 2003”).  

-On the Analytic Properties of the $z$-coloured Jones Polynomial, J. Knot Theory Ramifications  14  (2005),  no. 4, 435--466.



Other work
(comments are very welcome):

-On 2-Dimensional Homotopy Invariants of Complements of Knotted Surfaces. This is an archaic version of "The Fundamental Crossed Module of the Complement of a Knotted Surface", using movies with bands and spanners rather than hyperbolic splittings of knotted surfaces in the construction. May still be of interest.



Conferences / workshops (past and future):

- XVIIIth Oporto Meeting on Geometry, Topology and Physics (July 8-12, 2009) at the Oporto University Main Theme: Symplectic and Poisson Geometry


-Higher Gauge Theory, TQFT and Quantum Gravity, Lisbon, 10-13 February, 2011 (Workshop), 7-13 February, 2011 (School)


- Recent Advances in Topological Quantum Field Theory (TQFT-2012) A one-week workshop on Topological Quantum Field Theory and Quantum Gravity, to be held at the University of Lisbon on September 10–14, 2012

Talk slides (comments are very welcome):

Categorifying the Knizhnik-Zamolodchikov Connections 3Quantum: Algebra Geometry Information, Tallinn 10-13 July 2012 , session: Geometry and topology in quantum gravity

Teaching materials -- in Portuguese (comments are very welcome)

Notas de AM2-D (séries e cálculo diferencial e integral em R^n)

Exercícios de Topologia