Andreas Vall

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Thirty-seven patients with inlay bone grafting for scaphoid nonunion were evaluated before and after operation for wrist function and carpal alignment. There were 26 in whom a palmar approach had been used. The remaining 11 had been treated with a dorsal approach. The two procedures showed a similar union rate (around 80%). The palmar approach, however,(More)
BACKGROUND Tumour stage was introduced to the Swedish Cancer Registry in 2004, but this key variable for prognostic research has not yet been validated. We validated the tumour stage data in surgically treated oesophageal cancer patients. MATERIAL AND METHODS Completeness and accuracy of tumour stage according to the TNM system ("Tumour Node Metastasis")(More)
In a general line with our first work [1], within hard thermal loop (HTL) approximation a general theory of the scattering for an arbitrary number of colorless plasmons off hard thermal particles of hot QCD-medium is considered. Using generalized Tsytovich correspondence principle, a connection between matrix elements of the scattering processes and a(More)
  • Andreas Vall, S . E . Korenblit, V . M . Leviant, A . V . Sinitskaya, A . B . Tanaev
  • 1997
Various exact solutions of two-particle eigenvalue problems for nonrelativistic contact four-fermion current-current interaction are obtained. Specifics of Goldstone mode is investigated. The connection between a renormalization procedure and construction of self-adjoint extensions is revealed.
  • Andreas Vall, S . E . KORENBLIT, V . M . LEVIANT, A . B . TANAEV
  • 2002
Exact solutions of Heisenberg equations and two-particle eigenvalue problems for the nonrelativistic four-fermion interaction and N,Θ model are obtained in the framework of a dynamical mapping method. Equivalence of different dynamical mappings is shown. 1. General consideration The main problem of QFT follows from the fact that any solutions of Heisenberg(More)
We suggest a simple analytical description of the S-wave isoscalar ππ amplitude, which corresponds to a joint dressing of the bare resonance and background contributions. The amplitude describes well the experimental data on the δ0 0 phase shift in the energy region below 900 MeV and has two poles in the Re s > 0 half-plane. Besides the well-known pole of(More)
Abstract In the context of semiclassical approximation a general formalism of deriving an effective current generating the bremsstrahlung of arbitrary number of soft gluons (longitudinal or transverse ones) in scattering of higher-energy parton off thermal parton in hot quarkgluon plasma with subsequent extension to two and more scatterers, is obtained. For(More)
  • Andreas Vall, S . E . Korenblit, V . M . Leviant, A . B . Tanaev
  • 1996
So, the correct definition of field equations (and Hamiltonian itself) implies some knowledge about qualitative properties of its solutions which in their turn depend on the form of these equations by a very singular manner. The usual way to go out from this closed circle is connected with perturbation theory. It is based on the assumption that product of(More)
  • Andreas Vall, S . E . Korenblit, V . M . Leviant, A . V . Sinitskaya
  • 1995
Vacuum structure, one-particle excitations’ spectra and bound states of these excitations are studied in frame of non-relativistic quantum field model with current × current type interaction. Hidden symmetry of the model is found. It could be broken or exact dependign on the coupling constant value. The effect of ”piercing” vacuum , generating the(More)
In the paper we consider non-relativistic analog of the Nambu-Jona-Lasinio model and demonstrate, by this most simplified example, the method of dynamical mappings of Heisenberg fields on ”physical” fields. We obtain the expressions for one particle eigen-excitation spectrum of full Hamiltonian (spectrum of ”clad” fermions), wave function of two(More)