Recent Papers


    The links refers to preprints at math arXiv. All my papers on arXiv can be found
  • here Published versions may be different. In some cases the files are missing due to copyright restrictions. Please write me if you want to have electronic or hard copies.
  • (with L. Suciu) Similarity problems, Folner sets and isometric representations of amenable semigroups ,  Preprint
  • (with M. Crouzeix and H. Klaja) Spectral sets and operator radii ,  Preprint
  • (with S. Grivaux) Kazhdan constants, continuous probability measures with large Fourier coefficients and rigidity sequences ,  Preprint
  • (with S. Grivaux) Kazhdan sets in groups and equidistribution properties ,  J. Funct. Anal.
  • (with L. Suciu) Harnack and Shmul'yan pre-order relations for Hilbert space contractions ,  Preprint.
  • (with D. Seifert) Ritt operators and convergence in the method of alternating projections ,  to appear in J. Approx Th.
  • (with L. Suciu, D. Timotin) Classes of contractions and Harnack domination ,  Preprint.
  • K-spectral sets: an asymptotic viewpoint.,  J. Appl. Funct. Anal. 9 (2014), no. 3-4, 239--250.
  • (with B. Beckermann) Spectral Sets,  Chapter 37, in Handbook of linear algebra. Edited by Leslie Hogben. Chapman and Hall/CRC, 2014.
  • (with M. Crouzeix) Numerical radius and distance to unitaries.,  Operator and Matrices.
  • (with S. Grivaux and V. Muller) A generalization of the Friedrichs angle and the method of alternating projections,  Comptes Rendus Math. 348(2010), 53-56.
  • (with S. Grivaux and V. Muller) The rate of convergence in the method of alternating projections,  Algebra i Analiz 23 (2011), no. 3, 1--30; translation in St. Petersburg Math. J. 23 (2012), no. 3, 413--434
  • (with Yu.I. Lyubich) Geometric, spectral and asymptotic properties of averaged products of projections in Banach spaces,  Studia Math.
  • (with S. Grivaux and V. Muller) Epsilon-hypercyclic operators,  Ergodic Theory Dynamical Syst. ; Oberwolfach Preprints.
  • (with B. Beckermann and M. Crouzeix) Intersections of several disks of the Riemann sphere as K-spectral sets,  Preprint ArXiv ; Comm Pure Appl. Math. (P.G. Ciarlet volume)
  • Bernstein Polynomials and Operator Theory,  Results in Math. (Birkhauser)
  • (with V. Muller) On weak orbits of operators,  Topology Appl, Jan Pelant memorial volume
  • (with S. Grivaux) Faber-hypercyclic operators,  Israel J. Math.
  • (with S. Grivaux) Size of the peripheral point spectrum under power or resolvent growth conditions,  J. Funct. Anal.
  • (with S. Grivaux) Unimodular eigenvalues, uniformly distributed sequences and linear dynamics,  Advances in Math
  • (with V. Muller) Subscalar operators and growth of resolvent,  J. Operator Th.
  • (with M. Mbekhta) Operators similar to partial isometries,  Acta Sci Math
  • (with V. Muller) Growth conditions and inverse producing extensions,  J. Operator Th.
  • (with M. Crouzeix, B. Delyon) Convex domains and K-spectral sets,  Math. Z.
  • (with V. Muller) Invertible extensions and growth conditions ,  C.R. Acd. Sci. Paris Ser. I 339(2004), 21-26.
  • Operators near completely polynomially dominated ones and similarity problems, J. Operator. Th., 49(2003), 3-23.
  • Perturbations of operators similar to contractions and the commutator equation ,  Studia Math. 150(2002), 273-293.
  • (with G. Cassier) Constrained von Neumann inequalities, Advances in Math. 166(2002), 260-297.
  • (with V. Paulsen) Schur multipliers and operator-valued Foguel-Hankel operators,  Indiana Univ. Math. J. 50(2001), 1509-1522.
  • (with M. Mbekhta) The stability radius of Fredholm linear pencils, J. Math. Anal. Appl., 260 (2001), no. 1, 159--172.
  • Stable ranks, K-groups and Witt groups of some Banach and C*-algebras,, Contemporary Math. (A.M.S.), 232(1999), 55-64.
  • (with M. Mbekhta) Compressions of resolvents and maximal radius of regularity, Trans. Amer. Math. Soc. 351(1999), 2949-2960.
  • (with M. Mbekhta) On existence of one-sided and generalized resolvents of bounded linear operators, in : Proc. International Workshop on Operator Theory, Cefaly, July 1997, (ed. by P. Aiena, M. Pavone and C. Trapani), 139-148, Palermo 1998.
  • The stable rank of topological algebras and a problem of R.G. Swan,Journal of Functional Analysis, 160 (1998), 42-78.
  • Sur les caracteres d'une algebre de Banach, Canad. Math. Bull. 40 (1997), 129-132.
  • (with M. Mbekhta) Generalized inverses and the maximal radius of regularity of a Fredholm operator, Integral Equat. Operator Th. 28 (1997), 133-146.
  • On some criteria of irrationality for series of positive rationals : a survey, in Actes ds rencontres Arithmetiques de Caen (a la memoire de Roger Apery), 2-3 juin 1995, 1-14. ;
  • (with C. Cottin, H. H. Gonska) Boegel functions, tensor products and blending approximation, Math. Nachr. 173 (1995), 25-48.
  • K-functionals and moduli of smoothness of functions defined on compact metric spaces, in Concrete Analysis, edited by G.A. Anastassiou, Academic Press, 1995, pp.23-31.
  • Banach algebras with the same K-theory and the same stable rank, IMRN - Internat. Math. Res. Notices 1994, no. 10, 401-414.
  • (with I. Rasa) The Gleason-Kahane-Zelazko property and Korovkin systems in symmetric involutive Banach algebras, Arch. Math. (Basel) 61 (1993), 163-169.
  • The Gleason - Kahane - Zelazko theorem, Proc. IInd Conf. Functional Anal., Aquafredda di Maratea 1993 , ed. by F. Altomare ; G. Mastroianni, 177-188.
  • Le theoreme de Gleason-Kahane-Zelazko et les spectres de Ransford, C. R. Acad. Sci. Paris Ser.I 313 (1991), 679-683.
  • (with C.Cottin) Korovkin-type theorems for generalized Boolean sum operators, Colloq. Math. Soc. J. Bolyai 58 (1991), 51-68, North-Holland, Amsterdam (ed K. Tandori ; J. Szabados)
  • On a Korovkin-type theorem for simultaneous approximation, J. Approx. Theory 62 (1990), 223-234.
  • (with D.Andrica) Gruss inequality for positive linear functionals, Period. Math. Hungar. 19 (1988), 155-167.
  • Note on a conjecture of P.D.T.A. Elliott, Archivum Math. 23 (1987), 21-24.


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