고려대학교 이과대학 수학과 Department of Mathematics, Korea University
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Linear connection in the space of composition operators over the ball (with H. Koo, W. Smith and P. T. Tien ), preprint. Schatten class difference of composition operators on the Bergman space (with K. Choi, H. Koo, and I. Park ), preprint. Littlewood-Paley type estimates and applications to composition operators (with H. Koo, E. Pozzi and W. Smith ), preprint. The reproducing kernel thesis for difference of Hardy-space composition operators over the ball (with K. Choi, H. Koo and I. Park ), preprint Compact difference of Fejer-Riesz composition operators (with H. Koo and W. Smith ), Potential Analysis, published online, May 29, 2025 Hilbert-Schmidt double differences of composition operators and non-rigid phenomenon (with X.Guo, T. Hosokawa, H. Koo, S. Ohno and M. Wang ), J. Math. Anal. Appl. 543(March 2025), Article 128843(40p) Difference of weighted composition operators over the ball (with K. Choi, H. Koo and I. Park ), Complex Analysis and Operator Theory, 18(Feb 2024) , Article 33(33p) Compact difference of composition operators on the Hardy spaces (with K. Choi, H. Koo and I. Park ), Trans. Amer. Math. Soc. Series B 9 (2022), 733-756 Linear connection between composition operators on the Hardy space (with K. Choi, H. Koo and I. Park ), J. Math. Anal. Appl. 515(1) (Nov 2022), Article 126402(39p) Invariant mean value property and M-harmonicity on the half-space (with K. Nam ), Bull. Korean Math. Soc. 58(3) (May 2021), 559-572 Difference of weighted composition operators II (with K. Choi, H. Koo and J. Yang ), Integral Equations Operator Theory 93(2) (Apr 2021), Article: 17(19p) Path components of composition operators over the half-plane (with H. Koo, W. Smith and P. T. Tien ), J. Math. Anal. Appl. 497(2) (May 2021), Article: 124861(35p) Difference of weighted composition operators (with K. Choi, H. Koo and J. Yang ), J. Functional Analysis 278(5) (Mar 2020), Article: 108401(38p) Compact linear combination of composition operators on Bergman spaces (with H. Koo and W. Maofa ), J. Functional Analysis 278(5) (Mar 2020), Article:108393(36p) New characterizations for the weighted Fock spaces (with K. Nam), Complex Analysis and Operator Theory 13(6) (Sep 2019), 2671-2686 Compact double differences of composition operators on the Bergman spaces over the ball(with H. Koo and J. Yang ), Tohoku Math. J. 71(4) (Dec 2019), 609-637Linear fractional composition operators over the half-plane (with H. Koo and W. Smith ), Integral Equations Operator Theory 90(3) (Jun 2018), Article:27(32p) Sarason’s composition operator over the half-plane (with H. Koo and W. Smith ), J. Math. Anal. Appl. 462 (Jun 2018)(2), 1309-1341Difference of composition operators over the half-plane (with H. Koo and W. Smith ), Trans. Amer. Math. Soc. 369(5) (May 2017), 3173-3205 Compact double differences of composition operators on the Bergman spaces (with H. Koo and M. Wang ), J. Functional Analysis 272(Mar 2017), 2273-2307 Compact linear combinations of composition operators induced by linear fractional maps (with H. Koo, M. Wang and J. Yang ), Math. Z. 280(3) (Aug 2015), 807-824 Fock-Sobolev spaces of fractional order (with H. Cho and H. Koo ), Potential Analysis 43(2)(Aug 2015), 199-240 Commuting Toeplitz operators with pluriharmonic symbols on the Fock space, (with W. Bauer and H. Koo ), J. Functional Analysis 268(10) (May 2015), 3017-3060Composition as an integral operator (with H. Koo and W. Smith ), Advances in Math. 273(Mar 2015), 149-187 Linear combinations of composition operators on the Fock-Sobolev spaces (with H. Cho and H. Koo ), Potential Analysis 41(Nov 2014), 1223-1246 Commutants of Toeplitz operators with radial symbols on the Fock-Sobole space (with J. Yang ), J. Math. Anal. Appl. 415(Jul 2014), 779-790 Compact differences of composition operators on the Bergman spaces over the ball (with H. Koo and I. Park ), Potential Analysis 40(Jan 2014), 81-102Weak Hopf lemma for the invariant Laplacian and related elliptic operators (with S. Cho and H. Koo ), J. Math. Anal. Appl. 408(Dec 2013), 576-588 Hardy Carleson measures and their dual Poisson-Szego transforms (with K. Izuchi and H. Koo ), Potential Analysis 38(Jan 2013), 143-168 Compact differences of composition operators over polydisks (with H. Koo and I. Park), Integral Equations Operator Theory 73(1) (May 2012), 57-91 Hilbert Schmidt differences of composition operators on the Bergman space (with T. Hosokawa and H. Koo ), Math. Z. 269(Dec 2011), 751-775A note on composition operators acting on holomorphic Sobolev spaces (with H. Koo and W. Smith ), Proc. Amer. Math. Soc. 139(Dec 2011), 4369-4375 Toeplitz products with pluriharmonic symbols on the Hardy space over the ball (with H. Koo and Y. J. Lee ), J. Math. Anal. Appl. 381(Sep 2011), 365-382 Double integral characterizations of harmonic Bergman spaces (with K. Nam ), J. Math. Anal. Appl. 379(Jul 2011) 889-909Finite rank products of Toeplitz operators on the harmonic Bergman space (with H. Koo and K. Na ), Rocky Mountain J. Math.41(1)(Jan 2011), 45-78 Positive Schatten-Herz class Toeplitz operators on the ball (with H. Koo and Y. J. Lee ), New York J. Math. 17a (Jan 2011), 113-125 Linear sums of two composition operators on the Fock space (with Kohei Izuchi and H. Koo ), J. Math. Anal. Appl. 369(1)(Sep 2010), 112-119 Optimal norm estimate of operators related to the harmonic Bergman projection on the ball (with H. Koo and K. Nam ), Tohoku Math. J. 62(Sep. 2010), 357-374 Carleson measures for Bergman spaces and their dual Berezin transforms (with H. Koo and M. Stessin ), Proc. Amer. Math. Soc. 137(12)(Dec 2009), 4143-4155 Berezin transform and Toeplitz operators on harmonic Bergman spaces (with K. Nam ), J. Functional Analysis 257(10)(Nov 2009), 3135-3166 Finite sums of Toeplitz products on the polydisk (with H. Koo and Y. J. Lee ), Potential Analysis 31(3)(Oct 2009), 227-255 Finite rank product theorems for Toeplitz operators on the half-space (with H. Koo and K. Nam ), J. Math. Soc. Japan 61(3)(Jul 2009), 885-919 Carleson measures via BMO (with H. Koo and M. Stessin ), Integral Equations Operator Theory 63(4)(Apr 2009), 501-520 On higher dimensional Luecking’s theorem, J. Math. Soc. Japan 61(1)(Jan 2009), 213-224 Positive Schatten class Toeplitz operators on the ball (with H. Koo and Y. J. Lee ), Studia Math. 189(1)(Nov 2008), 65-90 Finite rank Toeplitz products with harmonic symbols (with H. Koo and Y. J. Lee ), J. Math. Anal. Appl. 343(Jul 2008), 81-98 Sums of Toeplitz products with harmonic symbols (with H. Koo and Y. J. Lee ), Revista Mat. Iberoamericana 24(1)(Apr 2008), 43-70 Carleson measures for the area Nevanlinna spaces and applications (with H. Koo and W. Smith ), J. Anal. Math.104(1) (Jan 2008), 207-233 Note on atomic decompositions of harmonic Bergman functions (with Y. J. Lee ), Proceedings of the 15th ICFIDCAA; Complex Analysis and its Applications, Osaka Municipal Universities Press, OCAMI Studies Series 2(2007), 11-24.
Toeplitz operators and Herz spaces on the half-space (with K. S. Nam ), Integral Equations Operator Theory 59(4)(Dec 2007), 501-521 Positive Schatten(-Herz) class Toeplitz operators on the half-space (with H. Koo and Y. J. Lee ), Potential Analysis 27(1)(Aug 2007), 73-100 Positive Toeplitz operators of Schatten-Herz type (with H. Koo and K. Na), Nagoya Math. J. 185(2007), 31-62 Zero products of Toeplitz operators with n-harmonic symbols (with H. Koo and Y. J. Lee ), Integral Equations Operator Theory 57(2007), 43-66 Products of Bergman space Toeplitz operators on the polydisk (with Y. J. Lee, K. Nam and D. Zheng ), Math. Ann. 337(2007), 295-316 Note on the Berezin transform on Herz spaces, RIMS Kyokuroku 1519(2006), 21-37Composition operators on small spaces (with H. Koo and W. Smith ), Integral Equations Operator Theory 56(3)(2006), 357-380 Note on commuting Toeplitz operators on the pluriharmonic Bergman space (with K. S. Nam), J. Korean Math. Soc. 43(2006), No. 2, 259-269
Zero products of Toeplitz operators with harmonic symbols (with H. Koo ), J. Functional Analysis 233(2006), No. 2, 307-334 Commutants of analytic Toeplitz operators on the harmonic Bergman space (with Y. J. Lee ), Integral Equations Operator Theory 50(2004), 559-564 Projections for harmonic Bergman spaces and applications (with H. Koo and H. Yi ), J. Functional Analysis 216(2) (2004), 388-421 Toeplitz operators on harmonic Bergman spaces (with Y. J. Lee and K. Na ), Nagoya Math. J. 174(2004), 165-186 Positive Toeplitz operators from a harmonic Bergman space into another (with Y. J. Lee and K. Na ), Tohoku Math. J. 56(2004), 255-270 Commuting Toeplitz operators on the polydisk (with H. Koo and Y. J. Lee ), Trans. Amer. Math. Soc. 356(2004), 1727-1749 Moment vanishing properties of harmonic Bergman functions (with H. Koo and H. Yi ), J. Math. Anal. Appl. 296(2)(2003), 365-381Composition operators acting on holomorphic Sobolev spaces (with H. Koo and W. Smith ), Trans. Amer. Math. Soc. 355(2003), 2829-2855 Harmonic Bergman Functions as Radial Derivatives of Bergman Functions (with H. Koo and H. Yi ), Proc. Amer. Math. Soc. 131(2003), 401-408Carleson type conditions and weghted inequalities for harmonic functions (with H. Koo and H. Yi ), Osaka J. Math. 39(2002), 945-962
Positive Toeplitz operators between the harmonic Bergman spaces (with H. Koo and H. Yi ), Potential Analysis 17(2002), 307-335 Derivatives of harmonic Bergman and Bloch functions on the ball (with H. Koo and H. Yi ), J. Math. Anal. Appl. 260(2001), 100-123 The numerical range and normality of Toeplitz operators (with Y. J. Lee ), Far East J. Math., Special Volume(2001), Part I, 71-80
Bergman norm estimates of Poisson integrals (with H. Koo and H. Yi ), Nagoya Math. J. 161(2001), 85-125 Gleason’s problem for harmonic Bergman and Bloch functions on half-spaces (with H. Koo and H. Yi ), Integral Equations Operator Theory 36(2000), 269-287 Images of Hankel operators on the polydisk (with Y. J. Lee ), Bull. Australian Math. Soc. 59(1999), 403-40 8Commuting Toeplitz operators on the harmonic Bergman space (with Y. J. Lee ), Michigan Math. J. 46(1999) 163-174 Representation and interpolation theorems of harmonic Bergman functions on half-spaces (with H. Yi ), Nagoya Math. J. 151(1998), 51-89 Pluriharmonic symbols of essentially commuting Toeplitz operators (with Y. J. Lee ), Illinois J. Math. 42(1998), 280-293On $\mathcal M$-harmonic functions and their Carleson measures (with Y. J. Lee ), Glasgow Math. J. 40(1998), 273-289 Bloch-to-BMOA pullbacks on the disk (with W. Ramey & D. Ullrich ), Proc. Amer. Math. Soc. 125(1997), 2987-2996The essential spectra of Toeplitz operators with symbols in H^\infty +C (with Y. J. Lee ), Math. Japonica 45(1)(1997), 1-4
Fractional derivatives of Bloch functions, growth rate, and interpolation (with K. S. Rim ), Acta Math. Hungarica 72(1-2)(1996), 67-86 Norm and essential norm estimates of Toeplitz operators on the Bergman space (with Y. J. Lee ), Comm. Korean Math. Soc. 11(1996), No.4, 937-958
A Luecking type subspace, dualities and Toeplitz operators (with Y. J. Lee ), Acta Math. Hungarica 67(1995), 151-170 Compact Toeplitz operators with bounded symbols on the Bergman spaces (with Y. J. Lee ), J. Korean Math. Soc. 3(1994), 289-307
Pluriharmonic symbols of commuting Toeplitz operators (with Y. J. Lee ), Illinois J. Math. 37(1993), 424-436 Bocher’s theorem for M-harmonic functions, Houston J. Math. 18(1993), 539-549 On the boundary behavior of functions holomorphic on the ball (with H. O. Kim ), Complex Variables 20(1992), 53-62 The essential norms of composition operators, Glasgow Math. J. 34(1992), 143-155 A Functional equation of Pexider type, Funcialaj Ekvacioj 35 (1992), 255-259 Composition with a homogeneous polynomial (with J. S. Choa ), Bull. Korean Math. Soc. 29(1992), 57-63
A Littlewood-Paley type identity and a characterization of BMOA (with J. S. Choa ), Complex Variables 17(1991), 15-23 Derivatives of Hardy functions, Proc. Amer. Math. Soc. 110(1990), 781-788 Projections, the weighted Bergman spaces, and the Bloch space, Proc. Amer. Math. Soc. 108(1990 ), 127-136 An integral mean inequality for Hadamard products on the polydisc, Complex Variables 13(1990), 213-215 Cauchy integral equalities and applications, Trans. Amer. Math. Soc. 315(1989), 337-352 Composition property of holomorphic functions on the ball, Michigan Math. J. 36(1989), 289-301Weights induced by homogneous polynomials, Pacific J. Math. 139(1989), 225-240 Composition with bounded holomorphic functions, PhD Thesis (supervised by W. Rudin), University of Wisconsin, Madison, 1988.
An elementary proof of $\sum n^{-2}=\pi^2 /6$, Amer. Math. Monthly 94(1987), 662-663
