TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - Adjoint of sums and products of operators in Hilbert spaces
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 82
PY  - 2016
IS  - 1-2
SP  - 175
EP  - 191
PG  - 17
SN  - 0001-6969
DO  - 10.14232/actasm-015-809-3
UR  - https://m2.mtmt.hu/api/publication/3084669
ID  - 3084669
N1  - Cited By :11            
            Export Date: 7 September 2022
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Popovici, D
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - On the sum between a closable operator T and a T-bounded operator
JF  - ANNALES UNIVERSITATIS SCIENTIARUM BUDAPESTINENSIS DE ROLANDO EÖTVÖS NOMINATAE - SECTIO MATHEMATICA
J2  - ANN UNIV SCI BP R EÖTVÖS NOM SECT MATH
VL  - 58
PY  - 2015
SP  - 95
EP  - 104
PG  - 10
SN  - 0524-9007
UR  - https://m2.mtmt.hu/api/publication/3079729
ID  - 3079729
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - Characterizations of essentially self-adjoint and skew-adjoint operators
JF  - STUDIA SCIENTIARUM MATHEMATICARUM HUNGARICA
J2  - STUD SCI MATH HUNG
VL  - 52
PY  - 2015
IS  - 3
SP  - 371
EP  - 385
PG  - 15
SN  - 0081-6906
DO  - 10.1556/012.2015.52.3.1300
UR  - https://m2.mtmt.hu/api/publication/2969008
ID  - 2969008
N1  - Cited By :8            
            Export Date: 7 September 2022
AB  - An extension of von Neumann's characterization of essentially selfadjoint operators is given among not necessarily densely defined symmetric operators which are assumed to be closable. Our arguments are of algebraic nature and follow the idea of [1]. © 2015 Akadémiai Kiadó, Budapest.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - Operators having selfadjoint squares
JF  - ANNALES UNIVERSITATIS SCIENTIARUM BUDAPESTINENSIS DE ROLANDO EÖTVÖS NOMINATAE - SECTIO MATHEMATICA
J2  - ANN UNIV SCI BP R EÖTVÖS NOM SECT MATH
VL  - 58
PY  - 2015
SP  - 105
EP  - 110
PG  - 6
SN  - 0524-9007
UR  - https://m2.mtmt.hu/api/publication/3079747
ID  - 3079747
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Popovici, Dan
AU  - Sebestyén, Zoltán
TI  - On operators which are adjoint to each other
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 80
PY  - 2014
IS  - 1-2
SP  - 175
EP  - 194
PG  - 20
SN  - 0001-6969
DO  - 10.14232/actasm-012-857-7
UR  - https://m2.mtmt.hu/api/publication/3079525
ID  - 3079525
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - A reversed von Neumann theorem
JF  - ACTA SCIENTIARUM MATHEMATICARUM (SZEGED)
J2  - ACTA SCI MATH (SZEGED)
VL  - 80
PY  - 2014
IS  - 3-4
SP  - 659
EP  - 664
PG  - 6
SN  - 0001-6969
DO  - 10.14232/actasm-013-283-x
UR  - https://m2.mtmt.hu/api/publication/2853826
ID  - 2853826
N1  - Cited By :8            
            Export Date: 7 September 2022
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - CHARACTERIZATIONS OF SELFADJOINT OPERATORS
JF  - STUDIA SCIENTIARUM MATHEMATICARUM HUNGARICA
J2  - STUD SCI MATH HUNG
VL  - 50
PY  - 2013
IS  - 4
SP  - 423
EP  - 435
PG  - 13
SN  - 0081-6906
DO  - 10.1556/SScMath.50.2013.4.1252
UR  - https://m2.mtmt.hu/api/publication/2541922
ID  - 2541922
AB  - The purpose of this paper is to revise von Neumann's characterizations of selfadjoint operators among symmetric ones. In fact, we do not assume that the underlying Hilbert space is complex, nor that the corresponding operator is densely defined, moreover, that it is closed. Following Arens, we employ algebraic arguments instead of the geometric approach of von Neumann using the Cayley transform.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sebestyén, Zoltán
AU  - Tarcsay, Zsigmond
TI  - T∗T always has a positive selfadjoint extension
JF  - ACTA MATHEMATICA HUNGARICA
J2  - ACTA MATH HUNG
VL  - 135
PY  - 2012
IS  - 1-2
SP  - 116
EP  - 129
PG  - 14
SN  - 0236-5294
DO  - 10.1007/s10474-011-0154-7
UR  - https://m2.mtmt.hu/api/publication/2433949
ID  - 2433949
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Tarcsay, Zsigmond
TI  - Operator extensions with closed range
JF  - ACTA MATHEMATICA HUNGARICA
J2  - ACTA MATH HUNG
VL  - 135
PY  - 2012
IS  - 4
SP  - 325
EP  - 341
PG  - 17
SN  - 0236-5294
DO  - 10.1007/s10474-011-0185-0
UR  - https://m2.mtmt.hu/api/publication/2433953
ID  - 2433953
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Bacsó, Gábor
AU  - Tuza, Zsolt
TI  - Dominating cliques in P5-free graphs
JF  - PERIODICA MATHEMATICA HUNGARICA
J2  - PERIOD MATH HUNG
VL  - 21
PY  - 1990
IS  - 4
SP  - 303
EP  - 308
PG  - 6
SN  - 0031-5303
DO  - 10.1007/BF02352694
UR  - https://m2.mtmt.hu/api/publication/1674551
ID  - 1674551
N1  - Cited By :80            
            Export Date: 5 October 2019            
            Correspondence Address: Bacsó, G.Köztársaság Tér 1, Budapest, H-1081, Hungary
Cited By :80            
            Export Date: 21 January 2020            
            Correspondence Address: Bacsó, G.Köztársaság Tér 1, Budapest, H-1081, Hungary
AB  - All induced connected subgraphs of a graph G contain a dominating set of pair-wise adjacent vertices if and only if there is no induced subgraph isomorphic to a path or a cycle of five vertices in G. Moreover, the problem of finding any given type of connected dominating sets in all members of a class G of graphs can be reduced to the graphs G∈G that have a cut-vertex or do not contain any cutset S dominated by some s∈S. © 1990 Akadémiai Kiadó.
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  -