TY  - JOUR
AU  - Hassi, S
AU  - Sebestyén, Zoltán
AU  - De Snoo, HSV
TI  - On the nonnegativity of operator products
JF  - ACTA MATHEMATICA HUNGARICA
J2  - ACTA MATH HUNG
VL  - 109
PY  - 2005
IS  - 1-2
SP  - 1
EP  - 14
PG  - 14
SN  - 0236-5294
DO  - 10.1007/s10474-005-0231-x
UR  - https://m2.mtmt.hu/api/publication/2385737
ID  - 2385737
AB  - A bounded, not necessarily everywhere defined, nonnegative operator A in a Hilbert space script h sign is assumed to intertwine in a certain sense two bounded everywhere defined operators B and C. If the range of A is provided with a natural inner product then the operators B and C induce two new operators on the completion space. This construction is used to show the existence of selfadjoint and nonnegative extensions of B*A and C*A. © 2005 Akadémiai Kiadó, Budapest.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Stochel, Jan
TI  - Reflection symmetry and symmetrizability of Hilbert space operators
JF  - PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY
J2  - P AM MATH SOC
VL  - 133
PY  - 2005
IS  - 6
SP  - 1727
EP  - 1731 (electronic)
SN  - 0002-9939
DO  - 10.1090/S0002-9939-04-07705-6
UR  - https://m2.mtmt.hu/api/publication/2449194
ID  - 2449194
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kérchy, László
TI  - Generalized Toeplitz operators
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 68
PY  - 2002
IS  - 1-2
SP  - 373
EP  - 400
PG  - 28
SN  - 0001-6969
UR  - https://m2.mtmt.hu/api/publication/1049874
ID  - 1049874
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
TI  - Positivity of operator products
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 66
PY  - 2000
IS  - 1-2
SP  - 287
EP  - 294
PG  - 8
SN  - 0001-6969
UR  - https://m2.mtmt.hu/api/publication/3079529
ID  - 3079529
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kérchy, László
TI  - Operators with regular norm-sequences
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 63
PY  - 1997
IS  - 3-4
SP  - 571
EP  - 605
PG  - 35
SN  - 0001-6969
UR  - https://m2.mtmt.hu/api/publication/1049481
ID  - 1049481
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
TI  - Operator extensions on Hilbert space
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 57
PY  - 1993
IS  - 1-4
SP  - 233
EP  - 248
PG  - 16
SN  - 0001-6969
UR  - https://m2.mtmt.hu/api/publication/3079731
ID  - 3079731
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kérchy, László
TI  - Isometric asymptotes of power bounded operators
JF  - INDIANA UNIVERSITY MATHEMATICS JOURNAL
J2  - INDIANA U MATH J
VL  - 38
PY  - 1989
SP  - 173
EP  - 188
PG  - 16
SN  - 0022-2518
DO  - 10.1512/iumj.1989.38.38008
UR  - https://m2.mtmt.hu/api/publication/1048794
ID  - 1048794
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
TI  - ON RANGES OF ADJOINT OPERATORS IN HILBERT-SPACE
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 46
PY  - 1983
IS  - 1-4
SP  - 295
EP  - 298
PG  - 4
SN  - 0001-6969
UR  - https://m2.mtmt.hu/api/publication/3066108
ID  - 3066108
LA  - English
DB  - MTMT
ER  -