619 research outputs found

    Framework for finite alternative theories to a quantum field theory

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    Using the path-integral formalism, we generalize the 't Hooft-Veltman method of unitary regulators to put forward a framework for finite, alternative quantum theories to a given quantum field theory. Feynman-like rules of such a finite, alternative quantum theory lead to alternative, perturbative Green functions. Which are acceptably regularized perturbative expansions of the original Green functions, causal, and imply no unphysical free particles. To demonstrate that the proposed framework is feasible, we take the quantum field theory of a single, self-interacting real scalar field and show how we can alter, covariantly and locally, its free-field Lagrangian to obtain finite, alternative perturbative Green functions.Comment: 14 pages v.2: 15 pages; modified generating functional to include renormalization constants; v.3: some small corrections to synchronize with the printed versio

    Two basic problems posed by quantum scattering of fundamental particles

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    We put forward a finite theory of quantum scattering of fundamental particles without using auxiliary particles. It suggests that to avoid ultraviolet divergencies and model faster-than-light effects it suffices to appropriately change only the free-field Lagrangians while retaining their locality in space-time and Lorentz invariance. Using functions of two independent four-vector variables, we base this finite theory on the path-integral formalism on the four-dimensional space-time and the Lehmann-Symanzik-Zimmermann reduction formula.Comment: 19 pages, no figure

    Regularization of QED by a generalized 't Hooft and Veltman method

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    Generalizing the 't Hooft and Veltman method of unitary regulators, we demonstrate for the first time the existence of local, Lorentz-invariant, physically motivated Lagrangians of quantum-electrodynamic phenomena such that: (i) Feynman diagrams are finite and equal the diagrams of QED but with regularized propagators. (ii) N-point Green functions are causal. (iii) S-matrix relates only electrons, positrons and photons, is unitary and Lorentz-invariant, and conserves charge and total four-momentum.Comment: RevTeX, 5 pages, nofigures; changed title and changed and added few sentences to stress that this is an example, and to shortly explain the framework of the original 't Hooft and Veltman regularization metho

    Framework for finite alternative theories to a quantum field theory. II-Unitarity

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    We generalized the 't Hooft-Veltman method of unitary regulators to put forward a path-integral framework for finite, alternative theories to a given quantum field theory. And we demonstrated that the proposed framework is feasible by providing a finite alternative to the quantum field theory of a single, self-interacting real scalar field. Here we give two properties of self-energy that make the corresponding scattering matrix unitary. We show that the perturbative self-energy has these two properties at least up to the second order in the coupling constant

    Perturbative S-matrices that depend on parameters of a realistic regularization

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    We propose a partial answer to the question of what kind of ultrahigh-energy physics has to be taken into account to circumvent the appearance of ultraviolet divergencies; a more than sixty years old open question in quantum electrodynamics. To this end we introduce a new theoretical concept to the theory of quantum scattering: Perturbative S-matrices that depend on parameters of a realistic regularization--realistic in the sense of Pauli and Villars [Rev. Mod. Phys. 21, 434 (1949)]. We expect that these additional parameters may provide some new information about the physics of quantum scattering. There are such perturbative S-matrices also in the presence of non-renormalizable interaction terms with no counterterms

    Applications of the Lorentz-Abraham-Dirac equation in long-term dynamics

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    To improve the presentation we modified the title and used the framework of perturbation modeling of long-term dynamics so as to present the Lorentz-Abraham-Dirac equation as the lowest order, asymptotic differential relation for the velocity of a charged point-like mass. We formulated two propositions and added two references.Comment: PACS numbers: 03.50.De; 45.50.-j; 11.30.-j; 29.20.-c; 45.05.+x Keywords: Radiation-reaction force, particle trajectory; accelerators. arXiv admin note: substantial text overlap with arXiv:1005.394

    Realistic regularization of the QED Green functions

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    Generalizing the 't Hooft and Veltman method of unitary regulators, we demonstrate for the first time the existence of local, Lorentz-invariant, physically motivated Lagrangians of quantum-electrodynamic phenomena such that: (i) Feynman diagrams are finite and equal the diagrams of QED but with regularized propagators. (ii) N-point Green functions are C-, P-, and T-invariant up to a phase factor, Lorentz-invariant and causal. (iii) No auxiliary particles or parameters are introduced

    Modeling quantum scattering of fundamental particles by classical, deterministic processes

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    We point out that results obtained by M. Ribaric and L. Sustersic, hep-th/0403084, and by M. Blasone, P. Jizba and H. Kleinert, quant-ph/0409021, suggest that the path-integral formalism is the key to a derivation of quantum physics from classical, deterministic physics in the four-dimensional space-time. These results and the 't Hooft conjecture, hep-th/0104219, suggest to consider a relativistic, non-material medium, an ether, as a base for non-local hidden-variable models of the physical universe

    Transport-theoretic Extensions of Quantum Field Theories

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    We propose a new, transport-theoretic (tt) class of relativistic extensions of quantum field theories of fundamental interactions. Its concepts are inspired by Feynman's atomistic idea about the physical world and by the extension of fluid dynamics to shorter distances through the Boltzmann transport equation. The extending tt Lagrangians imply the original Lagrangians as path-integralwise approximations. By constructing a tt Lagrangian that extends a general gauge-invariant Lagrangian, we show that a tt extension of the standard model is feasible. We define a tt Lagrangian in terms of tt fields of the spacetime variable and an additional, four-vector variable. We explain the fields of quantum field theories as certain covariant, local averages of tt fields. Only two tt fields may be needed for modeling fundamental interactions: (i) a four-vector one unifying all fundamental forces, and (ii) a two-component-spinor one unifying all fundamental matter particles. We comment on the new physics expected within the tt framework put forward, and point out some open questions.Comment: 36 pages, no pictures, plain Te

    Search for an equation of motion of a classical pointlike charge

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    In 1892 H.A. Lorentz started the search for a classical equation of motion for pointlike charged particles that takes into account the radiation reaction force. This search culminated in the Lorentz-Abraham-Dirac equation of motion, which is not satisfactory since it exhibits self-acceleration causing runaway solutions. In spite of ongoing efforts for more than a century, there is yet no acceptable classical equation of motion for a pointlike charge, cf. the recent paper by Rohrlich and the comments about his proposal. So, it is still an open question how to augment continuous classical electrodynamics with the physical concept of pointlike charged particles. The pointlike charge is presently only a common and handy computational device, which we generalized by the expansions in terms of co-moving moments of time-dependent, moving charges and currents
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