# Bianca Dittrich

Perimeter Institute for Theoretical Physics

Areas of research:

### Affiliations

**University of Waterloo and University of Guelph**

PhD students who wish to be supervised by Perimeter Institute faculty normally apply through the PSI program. To apply directly to a PhD program, students should submit an application to the Physics and Astronomy Department at the University of Waterloo.

Students interested in pursuing an MSc degree should apply to Perimeter Institute's PSI program.

### Research Interests

Understanding the nature of space and time has been a central question for philosophy and physics throughout the centuries. Space time in its classical form underlies the formulations of quantum (field) theory as well as classical gravity. Yet we know today that both theories are incomplete and that classical space time should be replaced by quantum spacetime. With my research I am contributing towards the construction of a consistent theory of quantum gravity and towards an understanding of quantum space time.
My work focusses in particular on non-perturbative approaches of quantum gravity and here on how to obtain a theory of quantum gravity valid over all scales. Such a theory of quantum gravity needs to incorporate renormalization concepts in its very construction. Thus my work involves the understanding of renormalization in a background independent context and with it the development of a framework of how to consistently formulate and construct a theory of quantum gravity.
Arguable quantum gravity should be based on a Lorentzian (that is real time) path integral. Most path integrals evaluation techniques rely however on an Euclidianization (that is imaginary time).
I am developing techniques to evaluate Lorentzian path integrals in quantum gravity, and explore some foundational questions related to the Lorentzian path integral. This includes the investigation of causality properties and topology change in quantum gravity.
A partial list of subjects I am interested in:
Loop quantum gravity and spin foams.
Discrete geometries and diffeomorphism symmetry.
Renormalization in background independent theories and tensor network coarse graining.
Renormalization and tensor network techniques in lattice gauge theories.
New notions of quantum geometry derived from topological field theories.
Topological phases and defects.
Holographic formulations of quantum gravity.
Observables in covariant systems and general relativity.
The Lorentzian path integral in quantum gravity.
Causality properties in quantum gravity.

### Positions Held

- since 2012 University of Waterloo, Adjunct Professor
- since 2012 Perimeter Institute, Faculty Member
- 2011-2014 University of Guelph, Adjunct Professor
- 2009-2012 Max Planck Institute for Gravitational Physics, Potsdam, Max Planck Research Group Leader
- 2008-2009 Universiteit Utrecht, Marie Curie Fellow
- 2005 -2008 Perimeter Institute, Postdoctoral Research Fellow
- 2002-2005 Max Planck Institute for Gravitational Physics, Potsdam, and Perimeter Institute, PhD fellow of the German Merit Foundation

### Awards

- Discovery Accelerator Supplement Award (for researchers with a superior research program that is highly rated in terms of originality and innovation), 2017, NSERC,
- Early Researcher Award, 2014, Province of Ontario
- Marie Curie Fellowship, 2008-09, European Union
- Otto Hahn Medal for young scientists, 2007, Max Planck Society

### Recent Publications

- Jan de Boer, Bianca Dittrich, Astrid Eichhorn, Steven B. Giddings, Steffen Gielen, Stefano Liberati, Etera R. Livine, Daniele Oriti, Kyriakos Papadodimas, Antonio D. Pereira, Mairi Sakellariadou, Sumati Surya, Herman Verlinde, Frontiers of Quantum Gravity: shared challenges, converging directions (Snowmass Summer Study), arXiv: 2207.10618
- Johanna N. Borissova, Bianca Dittrich, Towards effective actions for the continuum limit of spin foams, arXiv: 2207.03307
- Bianca Dittrich, Athanasios Kogios, From spin foams to area metric dynamics to gravitons, arXiv: 2203.02409 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Jose Padua-Arguelles, Complex actions and causality violations: Applications to Lorentzian quantum cosmology, arXiv: 2112.15387 [gr-qc]
- Bianca Dittrich, Steffen Gielen, Susanne Schander, Lorentzian quantum cosmology goes simplicial, Class.Quant.Grav. 39 (2022) 035012, arXiv: 2109.00875 [gr-qc]
- Bianca Dittrich, Modified Graviton Dynamics From Spin Foams: The Area Regge Action, arXiv: 2105.10808 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Jose Padua-Arguelles, Effective Spin Foam Models for Lorentzian Quantum Gravity, Class.Quant.Grav. 38 (2021) 19, 195002, arXiv: 2104.00485 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Hal M. Haggard, Discrete gravity dynamics from effective spin foams, Class.Quant.Grav. 38 (2021) 14, 145023, arXiv: 2011.14468 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Hal M. Haggard, Effective Spin Foam Models for Four-Dimensional Quantum Gravity, Phys. Rev. Lett. 125 (2020) 231301, arXiv: 2004.07013 [gr-qc]
- William J. Cunningham, Bianca Dittrich, Sebastian Steinhaus,Tensor network renormalization with fusion charges: applications to 3d lattice gauge theory, Universe 6 (2020) 97, arXiv: 2002.10472 [hep-th]
- Seth K. Asante, Bianca Dittrich, Florian Girelli, Aldo Riello, Panagiotis Tsimiklis, Quantum geometry from higher gauge theory, Class. Quant. Grav. 37 (2020) 205001, arXiv: 1908.05970 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Florian Hopfmueller, Holographic formulation of 3D metric gravity with finite boundaries, Universe 5 (2019) 181 (Editor's choice), arXiv: 1905.10931 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Hal M. Haggard, Holographic description of boundary gravitons in (3+1) dimensions, JHEP 1901 (2019) 144 , arXiv: 1811.11744 [hep-th]
- Clement Delcamp, Bianca Dittrich, Towards a dual spin network basis for (3+1)d lattice gauge theories and topological phases, JHEP 1810 (2018) 023, arXiv: 1806.00456 [hep-th]
- Bianca Dittrich, Christophe Goeller, Etera R. Livine, Aldo Riello, Quasi-local holographic dualities in non-perturbative 3d quantum gravity, Class. Quant. Grav. 35 (2018) 13LT01 (highligthed in CQG+), arXiv: 1803.02759 [hep-th]
- Bianca Dittrich, Cosmological constant from condensation of defect excitations, Universe 4 (2018) 81 (Editor's choice), arXiv: 1802.09439 [gr-qc]
- Seth K. Asante, Bianca Dittrich, Hal M. Haggard, The Degrees of Freedom of Area Regge Calculus: Dynamics, Non-metricity, and Broken Diffeomorphisms, Class. Quant. Grav. 35 (2018) 135009 (highlighted in CQG+), arXiv: 1802.09551 [gr-qc]
- Bianca Dittrich, Christophe Goeller, Etera Livine, Aldo Riello, Quasi-local holographic dualities in non-perturbative 3d quantum gravity II - From coherent quantum boundaries to BMS3 characters, Nucl.Phys. B938 (2019) 878-934 , arXiv: 1710.04237 [hep-th]
- Bianca Dittrich, Christophe Goeller, Etera Livine, Aldo Riello, Quasi-local holographic dualities in non-perturbative 3d quantum gravity I - Convergence of multiple approaches and examples of Ponzano-Regge statistical duals, Nucl.Phys. B938 (2019) 807-877, arXiv: 1710.04202 [hep-th]
- Bianca Dittrich, (3 + 1)-dimensional topological phases and self-dual quantum geometries encoded on Heegaard surfaces, J. High Energ. Phys. 05 (2017) 123, arXiv: 1701.02037
- Clement Delcamp, Bianca Dittrich, Towards a phase diagram for spin foams, Class. Quant. Grav. 34 (2017) 225006, arXiv: 1612.04506
- Clement Delcamp, Bianca Dittrich, Aldo Riello, On entanglement entropy in non-Abelian lattice gauge theory and 3D quantum gravity, J. High Energ. Phys. 11 (2016) 102, arXiv: 1609.04806
- Bianca Dittrich, Erik Schnetter, Cameron J. Seth, Sebastian Steinhaus, Coarse graining flow of spin foam intertwiners, Phys. Rev. D94 (2016) 124050, arXiv: 1609.02429
- Clement Delcamp, Bianca Dittrich, Aldo Riello, Fusion basis for lattice gauge theory and loop quantum gravity, J. High Energ. Phys. 02 (2017) 061, arXiv: 1607.08881
- Clement Delcamp, Bianca Dittrich, From 3D TQFTs to 4D models with defects, J. Math. Phys. 58 (2017) 062302, arXiv: 1606.02384
- Bianca Dittrich, Marc Geiller, Quantum gravity kinematics from extended TQFTs, New J. Phys. 19 (2017) 013003 (New Journal of Physics highlight 2017), arXiv: 1604.05195
- Bianca Dittrich, Philipp A. Hoehn, Tim A. Koslowski, Mike I. Nelson, Can chaos be observed in quantum gravity?, Phys. Lett. B769 (2017) 554, arXiv: 1602.03237
- Valentin Bonzom, Bianca Dittrich, 3D holography: from discretum to continuum, J. High Energ. Phys. 3 (2016) 208, arXiv: 1511.05441
- Bianca Dittrich, Philipp A. Hoehn, Tim A. Koslowski, Mike I. Nelson, Chaos, Dirac observables and constraint quantization, arXiv: 1508.01947
- Benjamin Bahr, Bianca Dittrich, Marc Geiller, A new realization of quantum geometry, arXiv: 1506.08571
- Bianca Dittrich, Marc Geiller, Flux formulation of loop quantum gravity: Classical framework, Class. Quant. Grav. 31 (2015) 135016, arXiv: 1412.3752
- Bianca Dittrich, Sebastian Mizera, Sebastian Steinhaus, Decorated tensor network renormalization for lattice gauge theories and spin foam models, New J. Phys. 18 (2016) 053009, (New Journal of Physics highlight 2016 and IOPselect) arXiv: 1409.2407
- Bianca Dittrich, The continuum limit of loop quantum gravity - a framework for solving the theory, in "Loop Quantum Gravity - The First 30 Years," edited by A. Ashtekar and J. Pullin, World Scientic Publishing 2017, pp 153-179, arXiv: 1409.1450
- Bianca Dittrich, Wojciech Kaminski, Sebastian Steinhaus, Discretization independence implies non-locality in 4D discrete quantum gravity, Class. Quant. Grav. 31 (2014) 245009, (CQG highlight of 2014/15), arXiv: 1404.5288
- Bianca Dittrich, Marc Geiller, A new vacuum for Loop Quantum Gravity, Class. Quant. Grav. 32 (2015) 112001, (Highlighted in CQG+ and chosen for IOPselect), arXiv: 1401.6441
- Bianca Dittrich, Jeff Hnybida, Ising Model from Intertwiners, Ann. Inst. Henri Poincare Comb. Phys. Interact. 3 (2016) 363, arXiv: 1312.5646
- Bianca Dittrich, Mercedes Martin-Benito, Sebastian Steinhaus, Quantum group spin nets: refinement limit and relation to spin foams, Phys. Rev. D 90, 024058 (2014), arXiv: 1312.0905
- Bianca Dittrich, Sebastian Steinhaus, Time evolution as refining, coarse graining and entangling, New J. Phys. 16 (2014) 123041, arXiv: 1311.7565
- Bianca Dittrich, Wojciech Kaminski, Topological lattice field theories from intertwiner dynamics, arXiv: 1311.1798
- Bianca Dittrich, Mercedes Martín-Benito, Erik Schnetter, Coarse graining of spin net models: dynamics of intertwiners, New J. Phys. 15 (2013) 103004, arXiv: 1306.2987
- Valentin Bonzom, Bianca Dittrich, Bubble divergences and gauge symmetries in spin foams, Phys. Rev. D88 (2013) 124021, arXiv: 1304.6632
- Valentin Bonzom, Bianca Dittrich, Dirac's discrete hypersurface deformation algebras, Class. Quant. Grav. 30 (2013) 205013, arXiv: 1304.5983
- Bianca Dittrich, Philipp A Hoehn, Constraint analysis for variational discrete systems, J. Math. Phys. 54 (2013) 093505, arXiv: 1303.4294
- Bianca Dittrich, James P. Ryan, On the role of the Barbero-Immirzi parameter in discrete quantum gravity, Class.Quant.Grav. 30 (2013) 095015, arXiv: 1209.4892
- Bianca Dittrich, Frank Hellmann, Wojciech Kaminski, Holonomy Spin Foam Models: Boundary Hilbert spaces and Time Evolution Operators, Class.Quant.Grav. 30 (2013) 085005, arXiv: 1209.4539
- Benjamin Bahr, Bianca Dittrich, Frank Hellmann, Wojciech Kaminski, Holonomy Spin Foam Models: Definition and Coarse Graining, Phys.Rev. D87 (2013) 044048, arXiv: 1208.3388
- Bianca Dittrich, Carlos Guedes, Daniele Oriti, On the space of generalized fluxes for loop quantum gravity, (Selected as NJP monthly highlight), Class.Quant.Grav. 30 (2013) 055008, arXiv: 1205.6166
- Bianca Dittrich, From the discrete to the continuous - towards a cylindrically consistent dynamics, New J. Phys. 14 (2012) 123004, arXiv: 1205.6127
- Bianca Dittrich, How to construct diffeomorphism symmetry on the lattice, PoS (QGQGS 2011) 012, arXiv: 1201.3840
- Bianca Dittrich, Frank C. Eckert, Towards computationial insights into the large-scale structure of spin foams, J. Phys. Conf. Ser. 360 (2012) 012004, arXiv: 1111.0967
- Bianca Dittrich, Sebastian Steinhaus, Path integral measure and triangulation independence in discrete gravity, Phys.Rev. D85 (2012) 044032, arXiv: 1110.6866 [gr-qc]
- Bianca Dittrich, Frank C. Eckert, Mercedes Martin-Benito, Coarse graining methods for spin net and spin foam models, New J.Phys. 14 (2012) 035008, arXiv: 1109.4927 [gr-qc]
- Bianca Dittrich, Philipp A. Hoehn, Canonical Simplicial Gravity, Class.Quant.Grav. 29 (2012) 115009, arXiv: 1108.1974 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, James P. Ryan, Spin foam models with finite groups, arXiv: 1103.6264 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, Sebastian Steinhaus, Perfect discretization of reparametrization invariant path integrals, Phys.Rev. D83 (2011) 105026, arXiv: 1101.4775 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, Song He, Coarse graining theories with gauge symmetries: the linearized case, New J.Phys. 13 (2011) 045009, arXiv: 1011.3667 [gr-qc]
- Bianca Dittrich, James P. Ryan, Simplicity in simplicial phase space, Phys.Rev. D82 (2010) 064026, arXiv: 1006.4295 [gr-qc]
- Aristide Baratin, Bianca Dittrich, Daniele Oriti, Johannes Tambornino, Non-commutative flux representation for loop quantum gravity, Class. Quant. Grav. 28 (2011) 175011, arXiv: 1004.3450 [hep-th]
- Bianca Dittrich, Philipp A. Hoehn, From covariant to canonical formulations of discrete gravity, Class. Quant. Grav. 27 (2010) 155001, arXiv: 0912.1817 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, Breaking and restoring of diffeomorphism symmetry in discrete gravity, XXV Max Born Symposium: The Planck Scale, arXiv: 0909.5688 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, Regge calculus from a new angle, New J.Phys. 12 (2010) 033010, arXiv: 0907.4325 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, Improved and Perfect Actions in Discrete Gravity, Phys.Rev. D80 (2009) 124030, arXiv: 0907.4323 [gr-qc]
- Benjamin Bahr, Bianca Dittrich, (Broken) Gauge Symmetries and Constraints in Regge Calculus, Class.Quant.Grav. 26 (2009) 225011, (Chosen for IOPselect), arXiv: 0905.1670 [gr-qc]
- Bianca Dittrich, Diffeomorphism symmetry in quantum gravity models, Adv. Sci. Lett. 2 (2009) 151, arXiv: 0810.3594 [gr-qc]
- Bianca Dittrich, James P. Ryan, Phase space descriptions for simplicial 4d geometries, Class.Quant.Grav. 28 (2011) 065006, arXiv: 0807.2806 [gr-qc]
- Bianca Dittrich, Simone Speziale, Area-angle variables for general relativity, New J.Phys. 10 (2008) 083006, (New Journal of Physics Best of 2008), arXiv: 0802.0864 [gr-qc]
- Bianca Dittrich, Thomas Thiemann, Are the spectra of geometrical operators in Loop Quantum Gravity really discrete?, J.Math.Phys. 50 (2009) 012503, arXiv: 0708.1721 [gr-qc]
- Bianca Dittrich, Laurent Freidel, Simone Speziale, Linearized dynamics from the 4-simplex Regge action, Phys.Rev. D76 (2007) 104020, arXiv: 0707.4513 [gr-qc]
- Bianca Dittrich, Johannes Tambornino, Gauge invariant perturbations around symmetry reduced sectors of general relativity: Applications to cosmology, Class. Quant. Grav. 24 (2007) 4543-4586, arXiv: gr-qc/0702093
- Bianca Dittrich, Johannes Tambornino, A perturbative approach to Dirac observables and their space-time algebra, Class. Quant. Grav. 24 (2007) 757-784, arXiv: gr-qc/0610060
- Bianca Dittrich, Partial and Complete Observables for Canonical General Relativity, Class.Quant.Grav. 23 (2006) 6155-6184, arXiv: gr-qc/0507106
- Bianca Dittrich, Renate Loll, Counting a black hole in Lorentzian product triangulations, Class. Quant. Grav. 23 (2006) 3849-3878, arXiv: gr-qc/0506035
- Bianca Dittrich, Thomas Thiemann, Testing the Master Constraint Programme for Loop Quantum Gravity V. Interacting Field Theories, Class. Quant. Grav. 23 (2006) 1143-1162, arXiv: gr-qc/0411142
- Bianca Dittrich, Thomas Thiemann, Testing the Master Constraint Programme for Loop Quantum Gravity IV. Free Field Theories, Class. Quant. Grav. 23 (2006) 1121-1142, arXiv: gr-qc/0411141
- Bianca Dittrich, Thomas Thiemann, Testing the Master Constraint Programme for Loop Quantum Gravity III. SL(2,R) Models, Class.Quant.Grav. 23 (2006) 1089-1120, arXiv: gr-qc/0411140
- Bianca Dittrich, Thomas Thiemann, Testing the Master Constraint Programme for Loop Quantum Gravity II. Finite Dimensional Systems, Class.Quant.Grav. 23 (2006) 1067-1088, arXiv: gr-qc/0411139
- Bianca Dittrich, Thomas Thiemann, Testing the Master Constraint Programme for Loop Quantum Gravity I. General Framework, Class. Quant. Grav. 23 (2006) 1025-1066, arXiv: gr-qc/0411138
- Bianca Dittrich, Partial and complete observables for Hamiltonian constrained systems, Gen. Rel. Grav. 39 (2007) 1891-1927, arXiv: gr-qc/0411013
- Bianca Dittrich, Renate Loll, A Hexagon model for 3-D Lorentzian quantum cosmology, Phys.Rev. D66 (2002) 084016, arXiv: hep-th/0204210

### Seminars

- Effective spin foam models and effective actions for their continuum limit, Loops 2021+1, Lyon, plenary talk, July 2022
- Areas as fundamental variables for gravity, Online workshop: Informational architecture of spacetime, OIST, invited talk, May 2022
- Complex action and causality violations in Lorentzian gravity, University of Mainz, seminar Jan 2022
- The future of spin foams, International Loop Quantum Gravity Seminar, invited panel member, Dec 2021
- Complex Regge action and topology change in Lorentzian gravity, Seminar, Radboud University, Dec 2021
- Exploring Lorentzian quantum gravity via effective spin foams, Particle-Cosmo Seminar, University of Heidelberg, seminar, Dec 2021
- Overcoming the anomaly in loop quantum gravity, Non-local QG seminar @Lyon, invited talk, Oct 2021
- Loop quantum gravity - a status report, Inaugural workshop of the International Society for Quantum Gravity, Online workshop, Oct 2021
- Exploring Lorentzian quantum gravity via effective spin foams, Radboud University, seminar, Sep 2021
- Modified graviton dynamics from spin foams: the Area Regge action, Centre de Physique Theorique Marseille, seminar, June 2021
- Quantization of space time and its effective dynamics, Universidade Federal do Rio Grande do Norte, seminar, June 2021
- Quantization of space time and its (effective) dynamics, University of Sheffield, April 2021
- Quantum discreteness of geometry and its surprising consequences, Workshop: Quantum Spacetime and the Renormalization Group, CP3-Origins, Odense, invited talk, Oct 2020
- Can spin foams work?, Radboud University, seminar, June 2020
- Quantum geometry from higher gauge theory, PennState University, seminar, Dec 2019
- Engineering quantum geometries, Workshop: Quantum Gravity and Quantum Geometry, Radboud University, invited talk, Oct 2019
- Quantum geometry from higher gauge theory, Radboud University, seminar, Oct 2019
- Holographic duals from quantum gravity, Imperial College, seminar, Oct 2019
- Quantum space time engineering, Univ. of York, seminar, Oct 2019
- Quantum geometry from higher gauge theory, Univ. of Nottingham, seminar, Sep 2019
- Quantum geometry from higher gauge theory, ILQGS seminar, Sep 2019
- Quantum geometry from higher gauge theory, Conference: Twistors and Loops, CIRM, Marseille, France, invited talk Sep 2019
- Deriving holographic duals and their tensor network representations from quantum gravity, Albert Einstein Institute, Potsdam, seminar, Aug 2019
- Holography for general boundaries, Quantum and Gravity in Okinawa, OIST, Japan, invited talk, July 2019
- Holography for general boundaries, Workshop: Gravity and other fields under the volcano, Catania, Italy, invited talk, June 2019
- Holography in loop quantum gravity, Loops 19, PennState, USA, plenary talk, June 2019
- Holographic description of boundary gravitons, ILQGS seminar, Nov 2018
- A dual field theory for boundary gravitons in 4D, Workshop: Quantum Gravity meets Lattice QCD, ETC* Trento, invited talk, Sep 2018
- Holography for Pedestrians, Workshop on Quantum Fields (Martin Reuter Fest), Mainz Institute for Theoretical Physics, invited talk, Sep 2018
- Constructing holographic duals from quantum gravity, NEB 18: Recent developments in gravity and relativity, Rhodes, invited talk, Sep 2018
- Holographic dualities in non-perturbative 3D gravity: from spin chains to BMS characters, Universite Libre de Bruxelles, seminar, July 2018
- Tensor networks: an overview, Radboud University, Nijmegen, seminar, July 2018
- Holographic dualities in non-perturbative 3D gravity: from spin chains to BMS characters, Radboud University, Nijmegen, seminar, June 2018
- Bootstrapping quantum gravity, WE-Heraeus Seminar Quantum spacetime and the Renormalization Group, Bad Honnef, invited talk, June 2018
- Accessing the dynamics of quantum gravity, Quantum Gravity on the Computer, NORDITA, invited talk, Mar 2018
- Introduction to special and general relativity, 30h course, AIMS Ghana, March 2018
- Cosmological constant from condensation of curvature defects, Perimeter Institute, seminar, Feb 2018
- Lifting (2+1)D topological theories to (3+1)D theories with defects, Workshop on higher gauge theory, University of Leeds, invited talk, Feb 2018
- Holographic dualities in non-perturbative 3D gravity: from spin chains to BMS characters, Syracuse University, seminar, Nov 2017
- Quantum geometry from topological quantum field theories with defects, Indiana University (Math Department), USA, colloquium, Oct 2017
- Bootstrapping quantum gravity, conference: Probing the space time fabric, SISSA, Italy, plenary talk, July 2017
- Bootstrapping quantum gravity, International Conference on Quantum Gravity, Loops 2017, Warsaw, Poland, plenary talk, July 2017
- Lifting (2+1)D topological theories to (3+1)D theories with defects, Part I and Part II, Tensor categories and field theories, workshop, Melbourne, Australia, invited talks, June 2017
- Quantum Space Time Engineering, Theory Canada 12, Conference, York University, Canada, invited talk, May 2017
- Self-dual quantum geometries and four-dimensional TQFTs with defects, ILQGS seminar, April 2017
- Introduction to special and general relativity, 30h course, AIMS Ghana, March 2017
- Quantum Space Time Engineering, University of Vienna, Austria, colloquium, Feb 2017
- Quantum Space Time Engineering, Riemann Conference, Univ. Muenster, invited talk, Oct 2016
- Entanglement entropy: spacetime glue?, Workshop: Emergent space time and cosmology, AEI Potsdam, invited talk, Sep 2016
- The many phases of loop quantum gravity, CarloFest, Marseille, invited talk, May 2016
- Constructing Quantum Space Time, Quantum Groups in Quantum Gravity Workshop, University of Waterloo, invited talk, Apr 2016
- New directions in loop quantum gravity, Albert Einstein Institute Potsdam, seminar Apr 2016
- 3D Holography: from discretum to continuum, Shapes of Gravity conference, Nijmegen, Invited talk, Mar 2016
- Loop quantum gravity as extended topological field theory, Fourth Tux Workshop on Quantum Gravity, Tux, Austria, invited talk Feb 2016
- 3D Holography: from discretum to continuum, ILQGS seminar, Sep 2015
- The consistent boundary formulation: renormalization and the flow of time, Problem of Time Workshop, LMU Munich, invited talk, July 2015, slides and video at http://www.problemoftime2015.philosophie.uni-muenchen.de/program/index.html
- Quantum Space Time Engineering, Itzykson Conference, IPhT Paris, invited talk, June 2015
- What can we observe and what can we know in quantum gravity?, KITP Program, Quantum Gravity Foundations: UV to IR, invited talk, Apr 2015
- What defines and how to construct a theory of quantum gravity, Workshop: Renormalization in quantum gravity, Nordita, invited talk, Mar 2015
- How to become a quantum space time engineer, UBC, colloquium, March 2015
- Continuum limit in (loop) quantum gravity, DESY Hamburg, Seminar, Jan 2015
- Continuum limit and renormalization flow in (loop) quantum gravity, Radboud University Nijmegen, Jan 2015
- Quantum Space Time Engineering, U Rochester, math-phys/ q-optics seminar, Dec 2014
- A new flux based representation for loop quantum gravity, Univ. Warsaw, seminar, Oct 2014
- The continuum limit of loop quantum gravity - A framework for solving the theory, Univ. Warsaw, seminar, Oct 2014
- Quantum Space Time, Graduate Days Univ. Heidelberg, 15h invited lecture course, Oct 2014
- Perfect discretizations, Workshop: Geometric Methods in Classical and Quantum Lattice Systems, Potsdam, invited talk, Sep 2014
- Quantum space time engineering, Workshop: Random Tensors, ESI, Vienna, Invited Talk, July 2014
- New Vacuum for Loop Quantum Gravity, MPI for Gravitational Physics, Potsdam, seminar, July 2014
- New quantum representation for loop quantum gravity, CPT Marseille, seminar, July 2014
- Quantum Space TIme Engineering, Atlantic GR conference, University of New Brunswick, invited talk, May 2014
- New vacuum and representation for Loop Quantum Gravity, Atlantic GR conference, University of New Brunswick, invited talk, May 2014
- Coarse graining and renormalization: the bottom up approach, Asymptotic Safety Online Seminar, Apr 2014
- Quantum Space Time Engineering, APS meeting, Savannah, USA, invited talk, April 2014
- Constructing Quantum Space Time, COST meeting on Fundamental Problems in Quantum Physics, Weizmann Institute, Israel, invited talk, March 2014
- Spin foams as a continuum theory, Second EFI winter conference on canonical and covariant LQG, Tux, Austria, invited talk, Feb 2014
- A new vacuum for loop quantum gravity, International Loop Quantum Gravity Seminar (online seminar series), Feb 2014, http://relativity.phys.lsu.edu/ilqgs/
- Diffeomorphism symmetry in the discrete and perfect discretizations, University of Waterloo, seminar, Jan 2014
- Triangulation invariant models from intertwiner dynamics, PennState University, Oct 2013
- Constructing a cylindrically consistent dynamics - building up a physical vacuum, PennState University, Oct 2013
- Where is canonical quantum gravity today?, Seminar on the Philosophical Foundations of Quantum Gravity, University of Illinois at Chicago, key note speaker, Sep 2013
- Towards the continuum limit of spin foam and spin net models, Quantum Gravity in the Southern Cone VI, São Paulo, invited talk, Sep 2013
- The continuum limit of spin foams and spin nets, GR 20, Warsaw, invited talk, July 2013
- Towards the continuum limit of spin foams and spin nets: renormalization flow in background independent theories, Quantum Gravity in Paris, invited talk, March 2013
- Coarse graining spin nets and spin foams: first results, AEI Potsdam, seminar, Jan 2013
- Coarse graining spin nets and spin foams: first results, Workshop: The search for quantum gravity: CDT and friends, Nijmegen, invited talk, Dec 2012
- Coarse graining: towards a cylindrically consistent dynamics, International Loop Quantum Gravity Seminar (online seminar series), Nov 2012, http://relativity.phys.lsu.edu/ilqgs/
- Canonical dynamics from holonomy spin foams, Group 29 Conference Tianjin, invited talk, Aug 2012
- From the discrete to the continuum -- towards a cylindrically consistent dynamics, ITP Universiteit Utrecht, seminar, May 2012
- From the discrete to the continuum -- towards a cylindrically consistent dynamics, Albert Einstein Institute Potsdam, seminar, May 2012
- Why spin foams are lattice gauge theories and why they are not, Workshop: Quantum gravity in Paris, LPT, invited talk, March 2012
- Towards the many particle regime of quantum gravity models: baby spin foams and nets, Albert Einstein Institute, Potsdam, seminar, Dec 2011
- Spin foams made very easy, Freie Universitaet Berlin, seminar, Nov 2011
- Towards the many particle regime of quantum gravity models: baby spin foams and nets, Workshop: Gravity as thermodynamics, Trieste, invited talk, Sep 2011
- Diffeomorphism symmetry, constraints and discretization independence in discrete gravity, Equadiff conference, Loughbourough, invited talk, Aug 2011
- Spin foam and spin net models, Summer school Quantum information meets statistical mechanic, El Escorial, invited lecture, Jul 2011
- Towards a large scale limit of (quantum gravity) models: baby spin foams and nets, Loops '11, Madrid, plenary talk, May 2011
- Dynamics and diffeomorphism symmetry in discrete quantum gravity, Spring meeting of the DPG, Karlsruhe, invited talk, Mar 2011
- Coarse graining , perfect actions and diffeomorphism symmetry, 3rd Quantum Gravity and Quantum Geometry School, Zakopane, invited lecture, Mar 2011
- Coarse graining and diffeomorphism symmetry, Workshop: From discrete to continuum spacetime in lattice QG and GFT, LPT Paris, invited talk, Mar 2011
- Dynamics and diffeomorphism symmetry in discrete quantum gravity, Workshop: Higher gauge theory topological qft and quantum gravity, Lisbon, invited talk, Feb 2011
- Diffeomorphism symmetry in quantum gravity, GR 19, Mexico City, invited talk, Jul 2010
- Quantum Space Time, IMPRSchool, Bollmannsruh, invited lecture, Jun 2010
- Diffeomorphism symmetry and triangulation independence in discrete gravity, Workshop: Open Problems in Loop Quantum Gravity, Zakopane, invited lecture, Mar 2010
- Diffeomorphism symmetry and perfect actions in discrete gravity, Univ. of Warsaw, seminar, Jan 2010
- Canonical kinematics and dynamics for simplicial geometries, Univ. of Warsaw, seminar, Jan 2010
- Complete observables: Introduction and perturbative framework, Univ. of Warsaw, lecture, Jan 2010
- Diffeomorphism symmetry and perfect actions in discrete gravity, Univ. of Edinburgh, seminar, Jan 2010
- Diffeomorphism symmetry and perfect actions in discrete gravity, Univ. Mainz, seminar, Dec 2009
- From discretized actions to discretized constraints, CPT Marseille, seminar, Nov 2009
- The fate of diffeomorphism symmetry in quantum gravity models, Emergent gravity IV, Vancouver, invited talk, Aug 2009
- Diffeomorphism symmetry and discreteness in quantum gravity, Loops 09, Beijing, plenary talk, Aug 2009,
- In search for diffeomorphism symmetry, Max Born Symposium: Physics at the Planck Scale, Wroclaw, contributed talk, Jul 2009
- Quantum gravity - problems and prospects, Univ. Essen-Duisberg, seminar, Jul 2009
- Diffeomorphism symmetry and discreteness, Workshop: Black Holes and Loop Quantum Gravity, Valencia, invited talk, Mar 2009
- Diffeomorphism symmetry in discrete quantum gravity, ENRAGE Young Quantum Gravity Meeting, Imperial College, invited talk, Jan 2009
- PIRSA:21060095, Space and Time in a Lorentzian path integral, 2021-06-15, Quantizing Time
- PIRSA:21020026, Welcome and Opening Remarks, 2021-02-22, Women at the Intersection of Mathematics and Theoretical Physics
- PIRSA:21010024, Towards Lorentzian quantum gravity via effective spin foams, 2021-01-28, Quantum Gravity
- PIRSA:20110038, Discussion Session 2, 2020-11-20, Tensor Networks: from Simulations to Holography III
- PIRSA:20110036, Tensor network description of 3D Quantum Gravity and Diffeomorphism Symmetry, 2020-11-18, Tensor Networks: from Simulations to Holography III
- PIRSA:20070000, Welcome and Opening Remarks, 2020-07-13, Quantum Gravity 2020
- PIRSA:20030114, Quantum Geometry vs. Quantum Gravity, 2020-03-19, Quantum Gravity
- PIRSA:20030056, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 6, 2020-03-13, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:20030055, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 5, 2020-03-11, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:20030054, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 4, 2020-03-10, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:20030053, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 3, 2020-03-06, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:20030052, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 2, 2020-03-05, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:20030051, PSI 2019/2020 - Quantum Gravity Part 1 - Lecture 1, 2020-03-03, PSI 2019/2020 - Quantum Gravity Part 1
- PIRSA:19110105, Closing Remarks and Good-Bye, 2019-11-22, Emmy Noether Workshop: The Structure of Quantum Space Time
- PIRSA:19110083, Welcome and Opening Remarks, 2019-11-18, Emmy Noether Workshop: The Structure of Quantum Space Time
- PIRSA:19030068, PSI 2018/2019 - Explorations in Quantum Gravity - Lecture 1, 2019-03-04, PSI 2018/2019 - Explorations in Quantum Gravity (Dupuis)
- PIRSA:18070053, Observables and (no) time in quantum gravity, 2018-08-01, Foundations of Quantum Mechanics
- PIRSA:17110131, Semi-classical evaluation of the 3D gravity path integral and quasi-local holography, 2017-11-13, The Path Integral for Gravity
- PIRSA:17080004, From 3D TQFTs to 4D models with defects, 2017-08-04, Hopf Algebras in Kitaev's Quantum Double Models: Mathematical Connections from Gauge Theory to Topological Quantum Computing and Categorical Quantum Mechanics
- PIRSA:17060085, Coarse-graining of Spin Foams - 4, 2017-06-22, Making Quantum Gravity Computable
- PIRSA:17060087, Tutorial: Coarse-graining of Spin Foams, 2017-06-22, Making Quantum Gravity Computable
- PIRSA:17060084, Coarse-graining of Spin Foams - 3, 2017-06-22, Making Quantum Gravity Computable
- PIRSA:17060060, Welcome and Opening Remarks, 2017-06-19, Making Quantum Gravity Computable
- PIRSA:17040008, Constructing Quantum Spacetime, 2017-04-26, Colloquium
- PIRSA:17040070, Self-dual quantum geometries and four-dimensional TQFTs with defects, 2017-04-18, Colloquium
- PIRSA:16070067, Entanglement Entropy in nonAbelian Gauge Theories, 2016-07-19, It from Qubit Summer School
- PIRSA:15110105, What is quantum space time?, 2015-11-26, PI Day - November, 2015
- PIRSA:15090080, What is a theory of quantum gravity?, 2015-09-29, Renormalization in Background Independent Theories: Foundations and Techniques
- PIRSA:15080082, 3D Holography: From discretum to continuum, 2015-08-21, Quantum Information in Quantum Gravity II
- PIRSA:15040091, Quantum Space Time Engineering, 2015-04-08, Colloquium
- PIRSA:15030128, New vacua and representations for loop quantum gravity, 2015-03-19, String Seminars
- PIRSA:15030011, Quantum Gravity Review-14, 2015-03-06
- PIRSA:15030010, Quantum Gravity Review-13, 2015-03-05
- PIRSA:15030009, Quantum Gravity Review-12, 2015-03-04
- PIRSA:15030008, Quantum Gravity Review-11, 2015-03-03
- PIRSA:15030007, Quantum Gravity Review-10, 2015-03-02
- PIRSA:15020060, Quantum Gravity Review-9, 2015-02-27
- PIRSA:15020059, Quantum Gravity Review-8, 2015-02-26
- PIRSA:15020058, Quantum Gravity Review-7, 2015-02-25
- PIRSA:15020057, Quantum Gravity Review-6, 2015-02-24
- PIRSA:15020056, Quantum Gravity Review-5, 2015-02-23
- PIRSA:15020053, Quantum Gravity Review-4, 2015-02-20
- PIRSA:15020052, Quantum Gravity Review-3, 2015-02-19
- PIRSA:15020051, Quantum Gravity Review-2, 2015-02-18
- PIRSA:15020050, Quantum Gravity Review-1, 2015-02-17
- PIRSA:14050119, New Vacuum and Representation For Loop Quantum Gravity, 2014-05-21, Quantum Gravity Day 2014
- PIRSA:14040089, Quantum Spacetime Engineering, 2014-04-22, Renormalization Group Approaches to Quantum Gravity
- PIRSA:14030021, 13/14 PSI - Quantum Gravity Review - Lecture 14, 2014-03-07
- PIRSA:14030020, 13/14 PSI - Quantum Gravity Review - Lecture 13
- PIRSA:14030019, 13/14 PSI - Quantum Gravity Review - Lecture 12
- PIRSA:14030018, 13/14 PSI - Quantum Gravity Review - Lecture 11
- PIRSA:14030017, 13/14 PSI - Quantum Gravity Review - Lecture 10, 2014-03-03
- PIRSA:14020071, 13/14 PSI - Quantum Gravity Review - Lecture 9, 2014-02-28
- PIRSA:14020070, 13/14 PSI - Quantum Gravity Review - Lecture 8, 2014-02-27
- PIRSA:14020069, 13/14 PSI - Quantum Gravity Review - Lecture 7, 2014-02-26
- PIRSA:14020068, 13/14 PSI - Quantum Gravity Review - Lecture 6, 2014-02-25
- PIRSA:14020067, 13/14 PSI - Quantum Gravity Review - Lecture 5, 2014-02-24
- PIRSA:14020064, 13/14 PSI - Quantum Gravity Review - Lecture 4, 2014-02-21
- PIRSA:14020063, 13/14 PSI - Quantum Gravity Review - Lecture 3, 2014-02-20
- PIRSA:14020062, 13/14 PSI - Quantum Gravity Review - Lecture 2, 2014-02-19
- PIRSA:14020061, 13/14 PSI - Quantum Gravity Review - Lecture 1, 2014-02-18
- PIRSA:14010112, Constructing Quantum Space Time, 2014-01-30,
- PIRSA:13120048, From spin foams to anyons and back again - Joint Condensed Matter/Quantum Gravity Seminar, 2013-12-05, Quantum Gravity
- PIRSA:13070079, Discrete Approaches - 3, 2013-07-25, Loops 13
- PIRSA:13020058, 12/13 PSI - Quantum Gravity Review Lecture 15, 2013-02-15
- PIRSA:13020057, 12/13 PSI - Quantum Gravity Review Lecture 14, 2013-02-14
- PIRSA:13020056, 12/13 PSI - Quantum Gravity Review Lecture 13, 2013-02-13
- PIRSA:13020055, 12/13 PSI - Quantum Gravity Review Lecture 12, 2013-02-12
- PIRSA:13020054, 12/13 PSI - Quantum Gravity Review Lecture 11, 2013-02-11
- PIRSA:13020051, 12/13 PSI - Quantum Gravity Review Lecture 10, 2013-02-08
- PIRSA:13020050, 12/13 PSI - Quantum Gravity Review Lecture 9, 2013-02-07
- PIRSA:13020049, 12/13 PSI - Quantum Gravity Review Lecture 8, 2013-02-06
- PIRSA:13020048, 12/13 PSI - Quantum Gravity Review Lecture 7, 2013-02-05
- PIRSA:13020047, 12/13 PSI - Quantum Gravity Review Lecture 6, 2013-02-04
- PIRSA:13020044, 12/13 PSI - Quantum Gravity Review Lecture 5, 2013-02-01
- PIRSA:13010092, 12/13 PSI - Quantum Gravity Review Lecture 4, 2013-01-31
- PIRSA:13010091, 12/13 PSI - Quantum Gravity Review Lecture 3, 2013-01-30
- PIRSA:13010090, 12/13 PSI - Quantum Gravity Review Lecture 2, 2013-01-29
- PIRSA:13010089, 12/13 PSI - Quantum Gravity Review Lecture 1, 2013-01-28
- PIRSA:12110051, Coarse graining: towards a cylindrically consistent dynamics, 2012-11-27, International Loop Quantum Gravity Seminar
- PIRSA:12100100, Is spacetime fundamentally discrete?, 2012-10-24, Experimental Search for Quantum Gravity 2012
- PIRSA:12020142, Coarse graining spin nets with tensor networks, 2012-02-09, Workshop: Computational Methods at Perimeter
- PIRSA:10030115, Geometro-kinematics and dynamics in a discrete setting, 2010-03-25, Quantum Gravity
- PIRSA:10030027, Diffeomorphism symmetry, triangulation independence and constraints in discrete gravity, 2010-03-24, Quantum Gravity
- PIRSA:10030026, Implications of background independence for quantum gravity, 2010-03-23, Quantum Gravity
- PIRSA:07120030, Introduction to Quantum Gravity, 2007-12-06, Quantum Gravity
- PIRSA:07050019, A Hamiltonian framework for cosmological perturbations to any order, 2007-05-01, Cosmology & Gravitation
- PIRSA:06110046, Approximate observables, 2006-11-28, International Loop Quantum Gravity Seminar
- PIRSA:04100037, Status of the Master Constraint Programme, 2004-10-30, Workshop on Quantum Gravity in the Americas: Status and future directions