Institute of Mathematics of the Romanian Academy,

Bucuresti, P.O. Box 1-764, RO-70700, ROMANIA

fax: (401)-222.98.26

Dept. of Theoretical Physics,

University of Bucharest,

P.O. Box MG 11, 76900-Bucharest, Romania

Ph.D. in Physics (1974)

- Professor of Theoretical Physics, University of Bucharest
- Senior Researcher at the i Institute of Mathematics of the Romanian Academy, Bucharest

Evolution Equations and Control Theory, Partial Differential Equations and Mathematical Physics

Mathematical Physics - quantum mechanics, statistical mechanics.

- Theory of strong interactions
- Rigorous results in quantum theory of solids
- Spectral theory for Schrodinger and Dirac operators
- Adiabatic invariants in classical and quantum mechanics
- Statistical mechanics

- Rigorous results in quantum theory of solids
- Spectral theory for Schrodinger and Dirac operators
- Adiabatic theorem of quantum mechanics

About the Best Stability in Weighted Dispersion RelationsNuovo Cim. Letters 4, 96-100 (1970)Absence of Spontaneous Magnetization in Isotropic Partially Finite SystemsPhys. Letters 33A, 422-423 (1971) (with G. Costache)On Non-existence of Spontaneous Magnetization in a One-dimensional Heisenberg FerromagnetPhys. Letters 34A, 422-423 (1971)The Asymptotic Expantion of the Displacement Field of Localised Defects in Cubic CrystalsCrystal Lattice Defects 2, 175-179 (1971) (with N. Angelescu and D. Grecu)On Stable PotentialsCommun. Math. Phys. 22, 162-165 (1971) (with N. Angelescu and V. Protopopescu)A Rigorous Lower Bound for the Maximum of Amplitude from Error-affected DataNuovo Cim. 8, 75-85 (1972) (with S. Ciulli)Molecular Field Theory and Phase Transitions in Partially Finite SystemsPhys. Stat. Solidi 51, 205-214 (1972) (with N. Angelescu and G. Costache)Weighted Dispersion Relations and Cut to Cut ExtrapolationsCommun. Math. Phys. 26, 237-246 (1972) (with S. Ciulli)Optimal Lower Bounds on the Hadronic Contribution to the Muon Anomalous Magnetic MomentNuovo Cim. 11A, 319-332 (1972) (with I. Raszillier)On the Ground state of Ising Chains with Finite Range InteractionsPhys. Lett. A43, 5,6 (1973) (with N. Angelescu and M. Bundaru)On the Independence of the Thermodynamic Limit on the Boundary Condition in Quantum Statistical MechanicsComm. Math. Phys. 29, 15-30 (1972) (with N. Angelescu)On the Surface Contribution to the Grand Canonical Pressure of Free Quantum GasesJ. Stat. Phys. 7, 119-130 (1973)The Schur-Pick-Nevanlinna Interpolation -an Alternative to N/D EquationsNucl. Phys. B53, 584-596 (1973)On Determinations of the KN Effective Coupling Constant from forward AmplitudeNucl. Phys. B59, 93-105 (1973) (with N. Sznajder Hald and J. L. Petersen)Optimal Information for the Pion Form Factor from Analiticity and Experimental DataNucl. Phys. B63, 285-300 (1973) (with I. Raszillier, W. Schmidt and H. Schneider)On the L2 Improperly Posed ProblemsJ. Math. Anal. App. 42, 132-137 (1973)Optimal Analytic Extrapolation for the Scattering Amplitude from Cuts to Interior PointsJ. Math. Phys. 14, 1675-1691 (1973) (with S. Ciulli)A New Method for the General Solution of Partial Wave Dispersion RelationsHelv. Phys. Acta 47, 137-162 (1974) (with G. Rasche and W. S. Woolcock)Eigenfunction Expantions for Schrodinger and Dirac Operators with Singular PotentialsCommun. Math. Phys. 42, 221-229 (1975)On the Landau DiamagnetismCommun. Math. Phys. 42, 9-28 (1975) (with N. Angelescu and M. Bundaru)On the Perturbations of Gibbs SemigroupsCommun. Math. Phys. 42, 29-30 (1975) (with N. Angelescu and M. Bundaru)Self-adjointness and Invariance of the Essential Spectrum for Dirac Operators Defined as Quadratic FormsCommun. Math. Phys. 48, 235-247 (1976)Self-adjointness and Invariance of the Essential Spectrum for Dirac Operators Defined as Quadratic FormsHelv. Phys. Acta 50, 1-4 (1977)On Regular External Fields in Quantum ElectrodynamicsHelv. Phys. Acta 51, 412-424 (1978) (with G. Scharf)General Solution of Multichannel Partial Wave Dispersion Relations. I. Coincident Thresholds, Pole ApproximationsHelv. Phys. Acta 51, 608 (1978) (with G. Rasche, M. Stihi and W. S. Woolcock)On the Adiabatic Limit for Dirac Particles in External FieldsCommun. Math. Phys. 76, 117-128 (1980)On the Adiabatic Theorem in Quantum MechanicsJ. Phys. A: Math. Gen. 13, L15 (1980)General Solution of Multichannel Partial Wave Dispersion Relations. II. Noncoincident Thresholds, One Pole approximationHelv. Phys. Acta 53, 134-158 (1980) (with G. Rasche and W. S. Woolcock)On the Dynamics of Bloch Electrons in External Electric FieldsPhys. Lett. 78A, 101 (1980) (with A. Nenciu)The critical Behaviour of the Kac Type Models for Semi-infinite SystemsJ. Stat. Phys. 24, 529-552 (1981) (with N. Angelescu, M. Bundaru and G. Costache)Adiabatic Theorem and Spectral Concentration. I. Arbitrary Order Spectral Concentration for the Stark Effect in Atomic PhysicsCommun. Math. Phys. 82, 121-136 (1981)Dynamics of Bloch Electrons in External Electric Fields: I. Bounds for Interband Transitions and Effective Wannier HamiltoniansJ. Phys. A: Math. Gen. 14, 2817, (1981) (with A. Nenciu)On the Order of Excitonic Phase TransitionPhys. Lett. A93, 201-204 (1983) (with N. Angelescu and N. S. Tonchev)Dynamics of Bloch Electrons in External Electric Fields: II. Existence of Strak-Wannier resonancesJ. Phys. A: Math. Gen. 15, 3313 (1982) (with A. Nenciu)The Existence of Energy gaps for Three Dimensional Systems without Long Range OrderJ. Phys. A Math. Gen.14, L109 (1981) (with A. Nenciu)A Lowner Type Interpolation Problem Applied to Partial Wave Dispersion RelationsHelv. Phys. Acta 56, 1046 (1983) (with G. Rasche)Removing Cut-offs Singular Perturbations: an Abstract ResultLett. Math. Phys. 7, 301 (1983)Applications of the Krein Resolvent Formula to the Theory of Self-adjoint Extensions of Positive Symmetric OperatorsJ. Operator Theory 10, 209 (1983)Existence of the Exponentially Localised Wannier FunctionsCommun. Math. Phys. 91, 81-85 (1983)On the Influence of the Reservoir and of the Shape of the Fermi Surface on the Phase Diagram of Two-band Models for Cr AlloysJ. Phys. F: Met. Phys. 14, 2155-2166 (1984) (with N. Angelescu and N. S. Tonchev)Stability of Energy Gaps under Variations of the Magnetic FieldLett. Math. Phys. 11, 127-132 (1986)Existence of Spontaneous Pair Creation in the External Field Approximation of Q.E.D.Commun. Math. Phys. 109, 303-312 (1987)Bloch Electrons in a Magnetic Field: Rigorous Justification of Peierls-Onsager Effective HamiltonianLett. Math. Phys. 17, 247-252 (1989)On the Nonrelativistic Limit if the Dirac HamiltonianAnn. Inst. Henri Poincare 51, 231-263 (1989) (with D. R. Grigore, and R. Purice)Existence of Stark-Wannier Resonances for Nonperiodic One-dimensional SystemsPhys. Rev. B40, 3622-3624 (1989) (with A. Nenciu)Adiabatic Theorems and Gell-Mann-Low FormulaHelv. Phys Acta 62, 372-388 (1989) (with G. Rasche)On the Theory of Adiabatic Invariants for Linear Hamiltonian SystemsComptes Rendus Acad. Sci. Paris, A310, 807-810 (1990) (with A. Boutet de Monvel)Dynamics of Band Electrons in Electric and Magnetic Fields: Rigorous Justification of Effective HamiltoniansRev. Mod. Phys. 63, 91-127 (1991)Asymptotic Invariant Subspaces, adiabatic theorems and block diagonalisationin:Recent Developments in Quantum Mechanics. Kluver, Dordrecht, 1991, p. 133-149Perturbation Theory for Time Dependent Hamiltonians: Rigorous Justification of the Effective HamiltoniansHelv. Phys. Acta 65, 529-559 (1992) (with Ph-A. Martin)Adiabatic Theorem for Non-Selfadjoint OperatorsJ. Phys A: Math. Gen. 25, 5741-5751 (1992) (with G. Rasche)Existence of Exponentially Localised Wannier Functions for Nonperiodic SystemsPhys. Rev. B47, 10112-10115 (1993) (with A. Nenciu)Linear Adiabatic Theory. Exponential EstimatesCommun. Math. Phys. 152, 479-496 (1993)Floquet Operators without Absolutely Continous SpectrumAnn. Inst. Henri Poincare 59, 91-97 (1993)Adiabatic Reduction Theory. Semiclassical S-Matrix for N-State One-dimensional SystemsOp. Theor.: Advances and Applications, 70, 307-319, (Birkhauser Verlag Basel) (1994)Semiclassical Inelastic S Matrix for One-dimensional N- States Systemsin:On Three Levels. NATO ASI Series B Physics, 234, 149-154. Ed: M. Fannes et all, Plenum, New-York (1994). (with Ph-A. Martin)On Adiabatic Reduction TheoryOp. Theory.: Adv. and Appl.78, 243-252, Birkhauser, Basel (1995). (with A. Martinez)Semi-classical Inelastic S-Matrix for One-dimensional N-States SystemsRev. Math. Phys. 7, 193-242 (1995) (with Ph. A. Martin)Perturbed Periodic Hamiltonians: Essential Spectrum and Exponential Decay of EigenfunctionsLett. Math. Phys. 34, 119-133 (1995). (with A. Boutet de Monvel and A. Nenciu)One-dimensional Dirac Hamiltonian: Semiclassical and High-energy Asymptotics for GapsJ. Math. Phys. 37, 3153-3167 (1996) (with R. Purice)Adiabatic Theory: Stability of Systems with Increasing GapsAnn. Inst. Henri PoincareExistence of generalised Wannier functions for one dimensional systemsCommun. Math. Phys. 190, 541-548 (1998) (with A. Nenciu)On Eigenfunction Decay for two Dimensional Magnetic Schrodinger OperatorsCommun. Math. Phys. 192, 671-685 (1998) (with H. Cornean)