Fredrik Viklund
Department of Mathematics, KTH Royal Institute of Technology
Department of Mathematics, KTH Royal Institute of Technology
Professor of mathematics at KTH Royal Institute of Technology.
My research interests lie in complex analysis, probability and mathematical physics. I'm a Wallenberg Scholar and supported by the Göran Gustafsson Foundation. Prior to returning to KTH, I was a Simons Fellow and Ritt Assistant Professor at Columbia University and then an associate professor at Uppsala University.
I'm part of the Simons Collaboration on Probabilistic Paths to QFT. Check back for activities and open positions.
I currently serve on the Scientific Council for Natural and Engineering Sciences at the Swedish Research Council (VR) and I'm a member of the KTH SCI school faculty board.
Editorial work: Arkiv för Matematik and Analysis and Mathematical Physics.
PhD students: Ellen Krusell, Vlad Guskov, Yan Luo (ETH, with Y. Wang), Lefteris Theodosiadis (with A. Sola, PhD 2024), Felix Rydell (with K. Kohn, PhD 2024), Lukas Schoug (PhD 2019).
Postdocs: Levi Haunschmid-Sibitz, Janne Junnila, Olof Rubin. Former postdocs: Mingchang Liu, Erik Duse, Malin Palö Forsström, Atul Shekhar.
I'm a member of the Random Matrix Theory and Random Geometry (RMRG) research group at KTH.
We run a weekly seminar: The KTH Probability and Mathematical Physics Seminar.
Upcoming call for postdocs in the RMRG group, Fall 2025. Write to me if you are interested.
Open position: Assistant Professor in Mathematical Analysis. Deadline Sept ??. The topic includes subareas of probability and mathematical physics.
New interactions between probability and geometry, IPAM/UCLA, Jan 26-30, 2026.
Random Explorations, on the occasion of Greg Lawler's 70:th birthday, IMSI/University of Chicago, July 6-10, 2026.
Quantum fields, Probability and Geometry, Institut Mittag-Leffler Program, February-May 2027.
Past events
Curves, Trees, Surfaces, on the occasion of Steffen Rohde's 60:th birthday. TU Berlin, June 2-6, 2025.
Utbildningsmässa, Rinkeby folkets hus, Friday Jan 24.
Mini workshop on Yang-Mills, Uppsala Center for Geometry and Physics, Jan 7-10, 2025.
Quantum Fields and Probability II, Institut Mittag-Leffler, July 15-19, 2024.
Call for postdocs in the RMRG group. Deadline was December 8, 2024.
Helsinki-Stockholm Probability and Mathematical Physics days 2024, Nov 28-29, NORDITA, Stockholm.
Jeju Island Workshop 2023: Random conformal geometry and related fields in Jeju
MSRI Semester, Spring 2022: The Analysis and Geometry of Random Spaces.
Quantum Fields and Probability, Institut Mittag-Leffler, August 8-12, 2022. Group photo.
Random growth: from lichen to lightning. Joint work with A. Sola and A. Turner made the cover of the London Mathematical Society Newsletter.
PhD courses
Reading course: Real and Complex analysis, 15 credits.
Spring 2025: Teichmuller theory. Course webpage.
Fall 2023: Quasiconformal mappings in the plane. (With A. Sola.)
Spring 2018, Fall 2020: Geometric Function Theory. (with A. Sola.)
Fall 2023: Gaussian fields and random surfaces. (Given by L. Schoug.)
My main areas of interest lie in complex analysis, probability, and mathematical physics, and especially problems where these areas meet. I am currently working on questions concerning Coulomb gases in the plane, the Loewner energy, Hele-Shaw flows, and lattice Yang-Mills theories.
Other topics of (past and present) interest are fine geometric properties of Schramm-Loewner evolution (SLE) curves; scaling limits of critical lattice models; Laplacian growth and aggregation models; analytic and probabilistic aspects of conformal field theory.
Planar Coulomb gas on a Jordan arc at any temperature
With K. Courteaut, K. Johansson
[arXiv]
A current expansion for Ising lattice gauge theory
With M. P. Forsström
[arXiv] (Not for publication.)
Competitive Hele-Shaw flow and quadratic differentials
With D. Witt Nyström
[arXiv]
Coulomb gas and the Grunsky operator on a Jordan domain with corners
With K. Johansson
[arXiv]
Free energy and quark potential in Ising lattice gauge theory via cluster expansion
With M. P. Forsström
Int. Math. Res. Not. (IMRN) 2025:12 (2025).
[arXiv]
Wilson lines in the lattice Higgs model at strong coupling
With M. P. Forsström, J. Lenells
Ann. Appl. Probab. 35: 1 (2025).
[arXiv]
Percolation for two-dimensional excursion clouds and the discrete Gaussian free field
With A. Drewitz, O. Elias, A. Prevost, J. Tykesson
Electron. J. Probab. 29 (2024)
[arXiv]
The Loewner-Kufarev Energy and Foliations by Weil-Petersson Quasicircles
With Y. Wang
Proc. London Math. Soc. 128:2 (2024)
[arXiv]
Wilson loops in the abelian lattice Higgs model
With M. P. Forsström, J. Lenells
Probability and Mathematical Physics (PMP) 4 (2) (2023)
[arXiv]
Wilson loops in finite Abelian lattice gauge theories
With M. P. Forsström, J. Lenells
Ann. Inst. Henri Poincaré 58 (4) 2129-2164 (2022)
[arXiv]
Conformal Field Theory at the Lattice Level: Discrete Complex Analysis and Virasoro Structure
With C. Hongler, K. Kytola.
Comm. Math. Phys. 395 1--58 (2022)
[arXiv] [Journal]
Convergence of loop-erased random walk in the natural parametrization
With G. F. Lawler.
Duke Math. J. 170 (10) (2021)
[arXiv] [Journal]
The Loewner difference equation and convergence of loop-erased random walk
With G. F. Lawler.
ALEA 19 (2022)
[Journal]
Dimensions of two-valued sets via imaginary chaos
With L. Schoug, A. Sepulveda
Int. Math. Res. Not. (IMRN) 2022 (5) (2022)
[arXiv] [Journal]
Remarks on the regularity of quasislits
With L. Schoug, A. Shekhar
Ann. Acad. Sci. Fenn. Math 46 (1) (2021)
[arXiv] [Journal]
Interplay between Loewner and Dirichlet energies via conformal welding and flow-lines
With Y. Wang
Geom. Funct. Anal. (GAFA) 30 289–321 (2020)
[arXiv] [Journal]
Asymptotic analysis of Dotsenko-Fateev integrals
With J. Lenells
Ann. Henri Poincaré 20 (11) 3799-3848 (2019)
[arXiv] [Journal]
Schramm's formula and the Green's function for multiple SLE
With J. Lenells
J. Stat. Phys. 176 (4) 873–931 (2019)
[arXiv]
Transition probabilities for infinite two-sided loop-erased random walks
With C. Benes, G. F. Lawler.
Electron. J. Probab. 24 Paper no 139, 22p (2019).
[arXiv]
One-dimensional scaling limits in a planar Laplacian random growth model
With A. Sola, A. Turner.
Comm. Math. Phys. 371 (1) (2019)
[arXiv] [Journal]
Convergence of radial loop-erased random walk in the natural parametrization
With G. F. Lawler
[arXiv]
A dimension spectrum for SLE boundary collisions
With T. Alberts, I. Binder.
Comm. Math. Phys 348 (1) 273–298, (2016)
[arXiv]
Scaling limit of the loop-erased random walk Green's function
With C. Benes, G. F. Lawler.
Probab. Theory. Related Fields, 166 (1-2), 271–319 (2016)
[arXiv]
Small particle limits in a regularized Laplacian random growth model
With A. Sola, A. Turner.
Comm. Math. Phys. 334 (1), 331-366, (2015)
[arXiv] [Simulations]
Convergence rates for loop-erased random walk and other Loewner curves
Ann. Probab. 43 (1), 119-165 (2015)
[arXiv]
On the continuity of SLE(k) in k
With S. Rohde, C. Wong.
Probab. Theory Related Fields 159 (3), 413-433 (2014)
[arXiv]
Some remarks on SLE bubbles and Schramm's two-point observable
With D. Beliaev.
Comm. Math. Phys. 320 (2), 379-394 (2013)
[arXiv]
Almost sure multifractal spectrum for the tip of an SLE curve
With G. F. Lawler.
Acta Math. 209, 265-322 (2012)
[arXiv]
On the rate of convergence of loop-erased random walk to SLE(2)
With C. Benes and M. Kozdron.
Comm. Math. Phys. 308 (2), 307-354 (2013)
[arXiv]
Optimal Holder exponent for the SLE path
With G. F. Lawler.
Duke Math. J. 159 (3), 351-383 (2011)
[Journal] [arXiv]
Scaling limits of anisotropic Hastings-Levitov clusters
With A. Sola and A. Turner.
Ann. Inst. Henri Poincaré 48, 235-257 (2012)
[Journal] [arXiv]
On the scaling limit of loop-erased random walk excursion
Ark. Mat. 50 (2) (2012)
[Journal]
Random Loewner Chains
Doctoral Thesis from KTH Royal Institute of Technology, April 2010.
Rescaled Levy-Loewner hulls and random growth
With A. Sola.
Bull. Sci. Math. 133, 238-256 (2009)
[Journal] [arXiv]
Email: frejo --at-- kth.se
Mailing Address:
Fredrik Viklund
Department of Mathematics, KTH Royal Institute of Technology
100 44 Stockholm, Sweden
Office:
Room 3527, Department of Mathematics, KTH
Drottning Kristinas Vag 25
Picture by Magnus Bergstrom/KAW