Igor Chueshov, Kharkov National University (Ucraina) Long-time behaviour of nonlinearly damped semilinear wave equation Lunedì 18 Aprile 2005, ore 17:00 Dipartimento di Matematica - Università degli Studi - Via Saldini 50 - Milano - Sala di Rappresentanza |
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Louis Nirenberg, Courant Institute, New York (Stati Uniti) A geometric problem and the Hopf Lemma Mercoledì 13 Aprile 2005, ore 17:00 Dipartimento di Matematica - Università degli Studi - Via Saldini 50 - Milano - Sala di Rappresentanza | |
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Francesco Baldassarri, Università di Padova Towards an algebraic proof of Deligne's regularity criterion Lunedì 04 Aprile 2005, ore 17:00 Dipartimento di Matematica - Università degli Studi - Via Saldini 50 - Milano - Sala di Rappresentanza |
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Abstract
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The point of the talk is that of providing purely algebraic definitions and proofs of otherwise known results on integrable systems of linear di erential equations with only a finite dimensional space of local solutions over a smooth algebraic manifold. This talk represents work in collaboration with Y. Andr´e and it is based on our joint book: “De Rham Cohomology of Di erential Modules on Algebraic Varieties”, Progress in Mathematics Vol. 189, Birkhaueser (2001). We correct some statements in that book. The result is still incomplete. Summary: 1. Review of the notion of regular singular point for a linear ordinary di erential equation with meromorphic coecients. Global counterpart “Fuchsian equations”) on a Riemann surface. 2. Examples: Hypergeometric equations on the projective complex line, with 3 singular points. 3. Generalisation of the notion of regular singularity along a divisor to integrable overdetermined systems of linear PDE’s over a complex algebraic manifold, and of the notion of fuchsian connection on an algebraic vector bundle. 4. Deligne’s canonical extension of a Fuchsian connection on a smooth complex algebraic variety, as a logarithmic connection with singularities along a divisor with normal crossings on a Hironaka compactification. 5. Deligne’s criterion of regularity on a normal (not necessarily smooth!) compactification: one only needs to consider the behaviour along the divisors at infinity. 6. (Counter)examples of J. Bernstein to some statements in loc. cit.. 6. Reduction process in a purely algebraic proof of 5. 1 |
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Nicola Varopoulos, Université de Paris VI (Francia) A classification of connected Lie groups in three different but equivalent ways Lunedì 14 Marzo 2005, ore 16:00 Dipartimento di Matematica e Applicazioni - Università degli Studi di Milano Bicocca - Via Cozzi, 53 - Aula 3014 |
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Joseph McKenna, University of Connecticut (Stati Uniti) Semilinear equations in analysis and mechanics: some history and recent progress Mercoledì 09 Marzo 2005, ore 17:00 Dipartimento di Matematica - Politecnico di Milano - Via Bonardi 9 - Milano - Aula Seminari VI piano |
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Filomena Pacella, Università di Roma La Sapienza Unicità della soluzione positiva di problemi ellittici semilineari e relativi problemi di autovalori Martedì 08 Marzo 2005, ore 17:00 Dipartimento di Matematica - Politecnico di Milano - Via Bonardi 9 - Milano - Aula Seminari VI piano |
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