List of publications

  1. I.Caprini, S,Ciulli, C.Pomponiu, I.Sabba Stefanescu, A bias-free method for the detection of bound, antibound and resonant states, Phys.Rev.D5(1972)1658-1661
    Abstract(pdf)
     
  2. S.Ciulli, C.Pomponiu, I.Sabba Stefanescu, G.Steinbrecher, Tautologies and optimisation of N/D equations, Phys.Rev.D8(1973) 455-467
    Abstract(pdf)
     
  3. I.Sabba Stefanescu, On the analytic extrapolation of scattering amplitudes in L2 norm, Nucl.Phys. B56(1973)287-300
    Abstract(pdf)
     
  4. S.Ciulli, C.Pomponiu, I. Sabba Stefanescu, G.Steinbrecher, CDD poles, inelasticities and optimisation of N/D equations, Nucl.Phys.B71(1974) 269-291
    Abstract(pdf)
     
  5. S.Ciulli, C.Pomponiu, I.Sabba Stefanescu, Some mathematical aspects of the problem of analytic extrappolation in elementary particle physics, in the Series "Physics of elementary particles and atomic nuclei", vol.6, no.1(1975)72 (in Russian)
    Abstract
     
  6. S.Ciulli, C.Pomponiu, I.Sabba Stefanescu, Analytic extrapolation techniques and stability problems in dispersion relation theory, Phys.Reports 17C, 135-224
    Abstract(pdf)
     
  7. C.B.Lang, I.Sabba Stefanescu, Analysis of the pion formfactor in the timelike region, Phys.Lett.58B (1975) 450-454
    Abstract(pdf)
     
  8. I.Raszillier, W.Schmidt, I.Sabba Stefanescu, Pionic contribution to the muon magnetic moment, Nucl.Phys.B109(1976) 452-468
    Abstract(pdf)
     
  9. I.Raszillier, W.Schmidt, I.Sabba Stefanescu, Can one detect zeroes of the pion formfactor? Z.Physik A277(1976)211-215
    Abstract(pdf)
     
  10. I.Raszillier, W.Schmidt, I.Sabba Stefanescu, On the zeroes of the pion electromagnetic formfactor, J.Math.Phys.17(1976)1957-1962
    Abstract(pdf)
     
  11. G.Höhler, E.Pietarinen, I.Sabba Stefanescu, F.Borkowski, G.G.Simon, V.H.Walther, R.D.Wendling, Analysis of the electromagnetic nucleon formfactors, Nucl.Phys.B114(1976) 505-534
    Abstract(pdf)
     
  12. C.B.Lang, I.Sabba Stefanescu, The π-K phase shifts and two variable analyticity, Phys.Lett.79B (1978) 479-482
    Abstract(pdf)
     
  13. G.Höhler, I.Sabba Stefanescu, Singularities of zero trajectories of scattering amplitudes, Z.Physik C2 (1979)253-263
    Abstract(pdf)
     
  14. I.Sabba Stefanescu, On the stable analytic continuation with rational functions, J.Math.Phys.21(1980) 175-188
    Abstract(pdf)
     
  15. I.Sabba Stefanescu, Constraints on phase shift analysis from two variable analyticity, Phys.Rev.D21(1980) 3225-3246
    Abstract(pdf)
     
  16. E.Borie, w.Gampp, G.Höhler, R.Koch, I.Sabba Stefanescu. The zero trajectories of invariant π-N amplitudes I, Z.Phys.C4(1980) 333-344
    Abstract(pdf)
     
  17. I.Sabba Stefanescu, On the determination of π-N phase shifts from isospin constraints and fixed t analyticity, Acta Phys.Austriaca, suppl.XXIII(1981)695-701
    Abstract(pdf)
     
  18. G.Höhler, I.Sabba Stefanescu, Zero trajectories and the slope of diffraction scattering, Phys.Rev.D25(1982)892-896
    Abstract(pdf)
     
  19. I.Sabba Stefanescu, On the determination of π-N phase shifts from isospin constraints and fixed t analyticity, J.Math.Phys.23(1982) 1190-1208
    Abstract(pdf)
     
  20. I.Sabba Stefanescu, On the convergence of reflectionless approximants to confining potentials, J.Math.Phys. 23(1982)2190-2204
    Abstract(pdf)
     
  21. I.Sabba Stefanescu, On the construction of amplitudes with Mandelstam analyticity from observable quantities, J.Math.Phys. 25(1984)2052-2085
    Abstract(pdf)
     
  22. I.Sabba Stefanescu, On the phase retrieval problem in two dimensions, J.Math.Phys.26(1985)2141-2160
    Abstract(pdf)
     
  23. D.Atkinson, I.S.Stefanescu, Truncation of continuum ambiguities in phase shift analysis, Commun.Math.Phys. 101(1985)291-304
    Abstract(pdf)
     
  24. I.Sabba Stefanescu, On the stable analytic continuation with a condition of uniform boundedness, J.Math.Phys.27(1986)2657-2686
    Abstract(pdf)
     
  25. I.Sabba Stefanescu, Zero trajectories and the problem of the reconstruction of the phase, Fortschr.Phys.35(1987) Nos.8-9, 573-673
    Abstract(pdf)
     
  26. I.Sabba Stefanescu, A problem of stability in phase shift analysis, Z.Physik C41(1988) 453-466
    PDF File
     
  27. I.S.Stefanescu, On the Duffing Equation at large forcing and damping ,in Computer Theoretikum und Praktikum für Physiker, 6(1993)146-150
    PDF File
     
  28. Ion Sabba Stefanescu, The Onset of Bifurcations in the Forced Duffing Equation with Damping, International Journal of Bifurcations and Chaos 23(2013)No.2,1330006(1-64)
    PDF File
     
 

PDF copies for all articles may be obtained on request

Some internal reports

  1. I.S.Stefanescu, On the Duffing equation at large forcing and damping, TKP90/11
    PDF file (13 MB)

    This report contains a proof of the theorem announced in Ref.27. Over the last year I have reconsidered this report, removed some (small) errors, improved some of the arguments and added some figures. The resulting work, "The onset of bifurcations in the forced Duffing equation with damping" appeared in the International Journal of Bifurcations and Chaos (no.28 above).

     
  2. I.S.Stefanescu, On the Duffing equation in the limit of large forcing and large damping, TKP89/11
    PDF file

    This report contains a proof that the Duffing equation admits of a unique periodic solution if the damping increases slightly quicker than logarithmically with the forcing.

     
  3. G.Höhler and I.S.Stefanescu, New approximate solutions to Duffing's equation, TKP 87-9E
    PDF file

    This is an introduction to the use of boundary layer methods in obtaining periodic solutions of Duffing's equation at large damping and forcing. The report contains many numerical examples.

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