In this paper we discuss some traps which can occur in using Dirac bra-ket notation in the coordinate (or momentum) representation. Furthermore, we demonstrate that in order to avoid some misconceptions, it is necessary to distinguish the two operators. First, the ordinary derivative , is just the usual partial differentiation which acts on the scalar function; and should not be considered as an operator which can act on the vectors in the Hilbert space. Second, unbounded operator , which is usually mixed up with the former. Our discussion indicates that the action of these two operators is the same on bra position , but on ket it really leads to different results.
Jafari Matehkolaee,M. (2025). On the coordinate representation in the Dirac bra-ket notation. Transactions in Theoretical and Mathematical Physics, 2(3), 160-164. doi: 10.30511/ttmp.2025.2065630.1060
MLA
Jafari Matehkolaee,M. . "On the coordinate representation in the Dirac bra-ket notation", Transactions in Theoretical and Mathematical Physics, 2, 3, 2025, 160-164. doi: 10.30511/ttmp.2025.2065630.1060
HARVARD
Jafari Matehkolaee M. (2025). 'On the coordinate representation in the Dirac bra-ket notation', Transactions in Theoretical and Mathematical Physics, 2(3), pp. 160-164. doi: 10.30511/ttmp.2025.2065630.1060
CHICAGO
M. Jafari Matehkolaee, "On the coordinate representation in the Dirac bra-ket notation," Transactions in Theoretical and Mathematical Physics, 2 3 (2025): 160-164, doi: 10.30511/ttmp.2025.2065630.1060
VANCOUVER
Jafari Matehkolaee M. On the coordinate representation in the Dirac bra-ket notation. TTMP, 2025; 2(3): 160-164. doi: 10.30511/ttmp.2025.2065630.1060
