Titlebook: Lectures on Quantum Field Theory and Functional Integration; Zbigniew Haba Textbook 2023 The Editor(s) (if applicable) and The Author(s),

拱墙

Interacting Fields and Scattering Amplitudes,of the derivation of the Gell-Mann-Low formula for quantum field correlation functions. The calculation at the second order of perturbation theory reveals the divergencies which can be cured by the mass and coupling constant renormalization. We show that divergencies are to be expected in higher ord

Obedient

Thermal States and Quantum Scalar Field on a Curved Manifold,ween these two topics as quantum fields in some moving frames (accelerated frames) can be viewed as thermal fields (the Unruh effect) and quantum fields on a black hole background have the thermal spectrum. We derive the formula for the correlation functions of the scalar quantum field in the quantu

有花

The Functional Integral,ace-time dimension. Feynman formulated his path integral integral on the physical basis of an interference of short time amplitudes. The composition of short time amplitudes has a mathematical version of the Trotter product formula. If the potentials and wave functions have an analytic continuation

并排上下

Feynman Integral in Terms of the Wiener Integral, can be considered as a way to treat the path integral. However, for some problems in quantum mechanics, e.g., the scattering and interference, we must work with a real time. Moreover, for potentials which are unbounded from below the imaginary time version is not applicable. For these reasons a rea

人类

Application of the Feynman Integral for Approximate Calculations,n . resulting in a direct way from the path integral. We formulate the semi-classical approximation as a stationary phase method of the calculation of integrals. We perform such an integral for harmonic and anharmonic oscillators. In application to QFT we show that the result of the stationary phase

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外星人

An Interaction with a Quantum Electromagnetic Field,e field strength variables are not sufficient. We need the vector potentials. The problem arises with the covariant quantization of the four-potentials. We must choose the correct number of degrees of freedom for quantization. We can distinguish physical components imposing a gauge condition. In thi

Pillory

BLA

Quantization of Non-Abelian Gauge Fields,gnetic potential of Chap. .. The solution involves a non-linear coupling of gauge field components. The coupling of gauge fields to matter fields together with the Higgs mechanism of mass generation led to the standard (Weinberg-Salam) model of particle physics which is the basis of the contemporary

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