Jani Virtanen
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+44 (0) 118 378 7930
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Professor
- School Director of Postgraduate Research Studies
- Undergraduate Seminar Organiser
- Lead of Pure Mathematics Group
Office
Room 211Building location
MathematicsTeaching
Current teaching (2021/22):
- MA1FM Foundations of Mathematics
- MA1RA1 Real Analysis I
- MA2RA1 Real Analysis I
Research centres and groups
Websites/blogs
Publications
- Hu, Z. and Virtanen, J. (2023) On the Berger-Coburn phenomenon. Operator Theory: Advances and Applications. Operator Theory: Advances and Applications Operator Theory: Advances and Applications ISSN: 2296-4878
- Chandler-Wilde, S. , Hagger, R. , Perfekt, K. , Virtanen, J. (2023) On the spectrum of the double-layer operator on locally-dilation-invariant Lipschitz domains. Numerische Mathematik , 153 pp. 653-699. ISSN: 0029-599X | doi: https://dx.doi.org/10.1007/s00211-023-01353-z
- Perälä, A. and Virtanen, J. (2023) Essential positivity. Proceedings of the American Mathematical Society ISSN: 0002-9939
- Arroussi, H. , Gissy, H. , Virtanen, J. (2023) Generalized Volterra type integral operators on large Bergman spaces. Bulletin des Sciences Mathématiques ISSN: 0007-4497 | doi: https://dx.doi.org/10.1016/j.bulsci.2022.103226
- Virtanen, J. (2022) On the product formula for Toeplitz and related operators. In: Basor, E. , Böttcher,, A. , Ehrhardt,, T. , Tracy, C. , (eds.) Toeplitz Operators and Random Matrices. Operator Theory: Advances and Applications , 289. Birkhäuser, Cham. (289). pp. 605-616. ISBN: 9783031138508 | doi: https://dx.doi.org/10.1007/978-3-031-13851-5_26
- Taskinen, J. and Virtanen, J. (2022) Boundedness of Toeplitz operators in Bergman-type spaces. In: Aron, R. , Moslehian, M. , Spitkovsky, I. , Woerdeman, H. , (eds.) Operator and Norm Inequalities and Related Topics. Trends in Mathematics Birkhäuser pp. 461-490. ISBN: 9783031021039 | doi: https://dx.doi.org/10.1007/978-3-031-02104-6_14
- Hu, Z. and Virtanen, J. (2022) IDA and Hankel operators on Fock spaces. Analysis & PDE ISSN: 1948-206X
- Taskinen, J. and Virtanen, J. (2022) Weak BMO and Toeplitz operators on Bergman spaces. New York Journal of Mathematics , 28 pp. 773-790. ISSN: 1076-9803
- Hu, Z. and Virtanen, J. (2022) Schatten class Hankel operators on the Segal-Bargmann space and the Berger-Coburn phenomenon. Transactions of the American Mathematical Society , 375 pp. 3733-3753. ISSN: 1088-6850 | doi: https://dx.doi.org/10.1090/tran/8638
- Hu, Z. and Virtanen, J. (2022) Fredholm Toeplitz operators on doubling Fock spaces. Journal of Geometric Analysis , 32 ISSN: 1050-6926 | doi: https://dx.doi.org/10.1007/s12220-021-00761-7
- Hagger, R. , Liu, C. , Taskinen, J. , Virtanen, J. (2022) Toeplitz operators on the unit ball with locally integrable symbols. Integral Equations and Operator Theory , 94 (2). ISSN: 1420-8989 | doi: https://dx.doi.org/10.1007/s00020-022-02695-3
- Gissy, H. , Miihkinen, S. , Virtanen, J. (2021) On the exponential integrability of conjugate functions. Journal of Fourier Analysis and Applications , 27 (87). ISSN: 1531-5851 | doi: https://dx.doi.org/10.1007/s00041-021-09885-4
- Ehrhardt, T. , Hagger, R. , Virtanen, J. (2021) Bounded and compact Toeplitz+Hankel matrices. Studia Mathematica , 2021 (260). pp. 103-120. ISSN: 0039-3223 | doi: https://dx.doi.org/10.4064/sm200806-6-10
- Hagger, R. and Virtanen, J. (2021) Compact Hankel operators with bounded symbols. Journal of Operator Theory , 86 (2). pp. 317-329. ISSN: 1841-7744 | doi: https://dx.doi.org/10.7900/jot.2020apr27.2276
- Brightmore, L. , Gehér, G. , Its, A. , Korepin, V. , Mezzadri, F. , Mo, M. , Virtanen, J. (2020) Entanglement entropy of two disjoint intervals separated by one spin in a chain of free fermion. Journal of Physics A: Mathematical and Theoretical , 53 ISSN: 1751-8113 | doi: https://dx.doi.org/10.1088/1751-8121/ab9cf2
- Taskinen, J. and Virtanen, J. (2020) On Fredholm properties of Toeplitz operators in Bergman spaces. Mathematical Methods in the Applied Sciences , 43 (16). pp. 9405-9415. ISSN: 0170-4214 | doi: https://dx.doi.org/10.1002/mma.6268
- Hu, Z. and Virtanen, J. (2020) Fredholm Toeplitz operators with VMO symbols and the duality of generalized Fock spaces with small exponents. Proceedings of the Royal Society of Edinburgh: Section A Mathematics , 150 (6). pp. 3163-3186. ISSN: 0308-2105 | doi: https://dx.doi.org/10.1017/prm.2019.65
- Al-Qabani, A. , Hilberdink, T. , Virtanen, J. (2020) Fredholm theory of Toeplitz operators on doubling Fock Hilbert spaces. Mathematica Scandinavica , 126 (3). pp. 593-602. ISSN: 1903-1807 | doi: https://dx.doi.org/10.7146/math.scand.a-120920
- Kozlowska, K. and Virtanen, J. (2019) Transition asymptotics of Toeplitz determinants and emergence of Fisher-Hartwig representations. Nonlinearity , 32 (10). pp. 3593-3645. ISSN: 1361-6544 | doi: https://dx.doi.org/10.1088/1361-6544/ab127a
- Miihkinen, S. and Virtanen, J. (2019) Toeplitz operators with piecewise continuous symbols on the Hardy space H 1. Arkiv för Matematik , 57 (2). pp. 429-435. ISSN: 1871-2487 | doi: https://dx.doi.org/10.4310/ARKIV.2019.v57.n2.a9
- Taskinen, J. and Virtanen, J. (2018) On compactness of Toeplitz operators in Bergman spaces. Functiones et Approximatio Commentarii Mathematici , 59 (2). pp. 305-318. ISSN: 0208-6573 | doi: https://dx.doi.org/10.7169/facm/1727
- Al-qabani, A. and Virtanen, J. (2018) Fredholm theory of Toeplitz operators on standard weighted Fock spaces. Annales Academiæ Scientiarum Fennicæ Mathematica , 43 pp. 769-783. ISSN: 1798-2383 | doi: https://dx.doi.org/10.5186/aasfm.2018.4344
- Virtanen, J. (2018) Double-scaling limits of Toeplitz determinants and Fisher-Hartwig singularities. In: Böttcher, A. , Potts, D. , Stollmann, P. , Wenzel, D. , (eds.) The Diversity and Beauty of Applied Operator Theory. Operator Theory: Advances and Applications Springer (268). pp. 495-504. ISSN: 0255-0156 ISBN: 9783319759951 | doi: https://dx.doi.org/10.1007/978-3-319-75996-8_29
- Taskinen, J. and Virtanen, J. (2018) On generalized Toeplitz and little Hankel operators on Bergman spaces. Archiv der Mathematik , 110 (2). pp. 155-166. ISSN: 1420-8938 | doi: https://dx.doi.org/10.1007/s00013-017-1124-2
- Ferro, R. and Virtanen, J. (2017) A note on structured pseudospectra of block matrices. Journal of Computational and Applied Mathematics , 322 pp. 18-24. ISSN: 0377-0427 | doi: https://dx.doi.org/10.1016/j.cam.2017.03.020
- Perälä, A. , Taskinen, J. , Virtanen, J. (2017) Toeplitz operators on Dirichlet-Besov spaces. Houston Journal of Mathematics , 43 (1). pp. 93-108. ISSN: 0362-1588 | doi: https://www.math.uh.edu/~hjm/Vol43-1.html
- Isralowitz, J. , Virtanen, J. , Wolf, L. (2015) Schatten class Toeplitz operators on generalized Fock spaces. Journal of Mathematical Analysis and Applications , 421 (1). pp. 329-337. ISSN: 0022-247X | doi: https://dx.doi.org/10.1016/j.jmaa.2014.05.065
- Perala, A. , Schuster, A. , Virtanen, J. (2014) Hankel operators on Fock spaces. Operator Theory: Advances and Applications , 236 pp. 377-390. ISSN: 0255-0156 | doi: https://dx.doi.org/10.1007/978-3-0348-0648-0_24
- Perala, A. , Virtanen, J. , Wolf, L. (2013) A Riemann-Hilbert problem with a vanishing coefficient and applications to Toeplitz operators. Concrete Operators , 1 (1). pp. 28-36. ISSN: 2299-3282 | doi: https://dx.doi.org/10.2478/conop-2012-0004
- Taskinen, J. and Virtanen, J. (2012) Weighted BMO and Toeplitz operators on the Bergman space A1. Journal of Operator Theory , 68 (1). pp. 131-140.
- Perälä, A. , Taskinen, J. , Virtanen, J. (2011) New results and open problems on Toeplitz operators in Bergman spaces. New York Journal of Mathematics , 17a pp. 147-164. ISSN: 1076-9803
- Perälä, A. and Virtanen, J. (2011) A note on the Fredholm properties of Toeplitz operators on weighted Bergman spaces with matrix-valued symbols. Operators and Matrices , 5 (1). pp. 97-106. ISSN: 1846-3886 | doi: https://dx.doi.org/10.7153/oam-05-06
- Perälä, A. , Taskinen, J. , Virtanen, J. (2011) Toeplitz operators with distributional symbols on Bergman spaces. Proceedings of the Edinburgh Mathematical Society , 54 (2). pp. 505-514. ISSN: 1464-3839 | doi: https://dx.doi.org/10.1017/S001309151000026X
- Perälä, A. , Taskinen, J. , Virtanen, J. (2011) Toeplitz operators with distributional symbols on Fock spaces. Functiones et Approximatio Commentarii Mathematici , 44 (2). pp. 203-213. ISSN: 0208-6573 | doi: https://dx.doi.org/10.7169/facm/1308749124
- Taskinen, J. and Virtanen, J. (2010) Toeplitz operators on Bergman spaces with locally integrable symbols. Revista Matemática Iberoamericana , 26 (2). pp. 693-706. ISSN: 0213-2230 | doi: https://dx.doi.org/10.4171/RMI/614
- Taskinen, J. and Virtanen, J. (2008) Spectral theory of Toeplitz and Hankel operators on the Bergman space A1. New York Journal of Mathematics , 14 pp. 305-323. ISSN: 1076-9803
- Papadimitrakis, M. and Virtanen, J. (2008) Hankel and Toeplitz transforms on H 1: continuity, compactness and Fredholm properties. Integral Equations and Operator Theory , 61 (4). pp. 573-591. ISSN: 0378-620X | doi: https://dx.doi.org/10.1007/s00020-008-1609-2
- Böttcher, A. and Virtanen, J. (2007) Norms of Toeplitz Matrices with Fisher-Hartwig Symbols. Siam Journal on Matrix Analysis and Applications ISSN: 0895-4798 | doi: https://dx.doi.org/10.1137/06066165X