Källén replies to Pauli's letter of the 2 February 1958 on the product of two or more field operators.
Källén, GunnarKällén talks about some calculations in connection with Lee's model.
Källén, GunnarKällén discusses eigenvalues of a Hamiltonian in his particle theory.
Källén, GunnarKällén writes on the prospect of publishing a paper on the Lee model together with Pauli and on some mathematical difficulties in connection with this model.
Källén, GunnarKällén sends a draft of their common paper with some remarks about the calculations.
Källén, GunnarKällén sends some details of his work (together with Pauli) on Lee's model of a renormalizable field theory.
Källén, GunnarKällén gives details of the mathematical technique of his work on quantum electrodynamics.
Källén, GunnarKällén discusses aspects of his theory on mass spectrum, and also the properties of functions. He makes some personal remarks about Jouvet.
Källén, GunnarKällén writes from CERN on the discontinuous character of the S-matrix for the transition to the dipole ghost.
Källén, GunnarKällén replies to Pauli's second question in his letter of 23 January.
Källén, Gunnar