The Källén–Lehmann spectral representation, or simply Lehmann representation, gives a general expression for the (time ordered) two-point function of an...

observable in the laboratory. If Källén–Lehmann spectral representation holds, at this stage we exclude gauge theories, the spectral density function can take...

Källén's research focused on quantum field theory and elementary particle physics. His developments included the so-called Källén–Lehmann spectral representation...

noted that the resulting gluon propagator does not admit a Källén–Lehmann spectral representation, which signals that the gluon cannot be a physical particle...

Kármán line Kármán vortex street Kármán–Howarth equation Källén–Lehmann spectral representation Köhler theory König's theorem (kinetics) Küssner effect...

second part of the zeroth axiom of Wightman is that the representation U(a, A) fulfills the spectral condition—that the simultaneous spectrum of energy–momentum...

quantization. The Bohr model successfully explained the discrete nature of atomic spectral lines. In 1924, Louis de Broglie proposed the hypothesis of wave–particle...

S2CID 207800450. Atiyah, Michael Francis; Patodi, V. K.; Singer, I. M. (1973), "Spectral asymmetry and Riemannian geometry", The Bulletin of the London Mathematical...

found by Schrödinger could predict the fine structure in the Hydrogen spectral series. The mysterious underlying property was spin. The first two-dimensional...

Field Theory. McGraw Hill. ISBN 978-0-07-154382-8. Moretti, V. (2017). Spectral Theory and Quantum Mechanics; Mathematical Foundations of Quantum Theories...