828 research outputs found
Geometry of syzygies via Poncelet varieties
No full textConsideriamo la Grassmanniana dei of -sottospazi lineari di
V_n=H^0({\P^1},\O_{\P^1}(n)). Definiamo la varietà
classificante i sistemi lineari di dimensione
e grado su le cui basi verificano un fissato numero di relazioni polinomiali di dato grado, ovvero un fissato numero di sizigie di dato grado. Nel presente lavoro calcoliamo la dimensione di .
Inoltre, studiamo il link tra le varietà di Poncelet.
In particolare, mostriamo che l'esistenza di sizigie lineari implica l'esistenza di singolarità sulle varietà di Poncelet.We consider the Grassmannian of -dimensional linear
subspaces of
V_n=H^0({\P^1},\O_{\P^1}(n)). We define
as the classifying space of the
-dimensional linear systems of degree on whose
basis realize a fixed number of polynomial relations of fixed
degree, say a fixed number of syzygies of a certain degree.
The first result of this paper is the computation of the dimension of .
In the second part we make a link between and the Poncelet varieties.
In particular, we prove that the existence of linear syzygies
implies the existence of singularities on the Poncelet varieties
Poncelet Porisms and Beyond
No full textThe goal of the book is to present, in a complete and comprehensive way, areas of current research interlacing around the Poncelet porism: dynamics of integrable billiards, algebraic geometry of hyperelliptic Jacobians, and classical projective geometry of pencils of quadrics. The most important results and ideas, classical as well as modern, connected to the Poncelet theorem are presented, together with a historical overview analyzing the classical ideas and their natural generalizations. Special attention is paid to the realization of the Griffiths and Harris programme about Poncelet-type p
Alfred Poncelet, S. J. Lettre inédite du P. Henri Samerius
No full textHumbert Auguste. Alfred Poncelet, S. J. Lettre inédite du P. Henri Samerius. In: Revue d'histoire de l'Église de France, tome 5, n°28, 1914. pp. 530-531
Poncelet a la presó de Saratov
No full textPoncelet va ser un militar francès que va formar part de les tropes napoleòniques que van perdre la batalla de Krasni a la campanya de Rússia. Durant el seu captiveri a la presó de Saratov, basant-se en el record de les lliçons inspiradores de Gaspard Monge a l'École Polytechnique, va reflexionar sobre els fonaments de la geometria projectiva i en va donar un punt de vista original que acabarà tenint una gran influència en el desenvolupament de la geometria al llarg del segle xix. Entre els seus resultats, el més conegut és l'anomenat porisma de Poncelet, que estudia l'existència de polígons amb vèrtexs en una cònica C i costats tangents a una altra cònica D en funció de la posició relativa de C i D. En aquest article repassem alguns fets de la vida de Poncelet i donem la idea d'una demostració del porisma
Quantitation of hemopoietic cell antigens in flow cytometry
No full textUsing appropriate standards immune flow cytometry permits quantitative analysis of the expression levels of cellular antigens. This information can be gained on an absolute basis and reported in terms of numbers of molecules per cell. This offers clues for reaching time-to-time and lab-to-lab comparability of immuno-fluorescence data. After briefly reminding the characteristics of available standards this paper provides an overview of the main relevant candidate molecules for flow cytometric quantitation on hemopoietic cells and reviews the major fields of application in immuno-hematology
Traité des proprietés projectives des figures
No full textVol. I (XXXII, 428 p., XII h. de plan. pleg.) -- Vol. II (VIII, 452 p., VI h. de plan. pleg.)Las h. de lam.: "J.-V. Poncelet del., Dembour sculp.", "J.-V. Ponvelet del., Dulos sc.
Geometry of syzygies via Poncelet varieties
No full textACLInternational audienceWe consider the Grassmannian of -dimensional linear subspaces of . We define as the classifying space of the -dimensional linear systems of degree on whose basis realize a fixed number of polynomial relations of fixed degree, say a fixed number of syzygies of a certain degree. The first result of this paper is the computation of the dimension of . In the second part we make a link between and the Poncelet varieties. In particular, we prove that the existence of linear syzygies implies the existence of singularities on the Poncelet varieties
Marco Martiniello et Marc Poncelet, dir. : Migrations et minorités ethniques dans l'espace européen, 1994
No full textDhoukar Hédi. Marco Martiniello et Marc Poncelet, dir. : Migrations et minorités ethniques dans l'espace européen, 1994. In: Hommes et Migrations, n°1176, mai 1994. L’étranger à la campagne. Figures de l’altérité en milieu rural. p. 54
Dirichlet and Neumann Problems for String Equation, Poncelet Problem and Pell-Abel Equation
No full textWe consider conditions for uniqueness of the solution of the Dirichlet or the Neumann problem for 2-dimensional wave equation inside of bi-quadratic algebraic curve. We show that the solution is non-trivial if and only if corresponding Poncelet problem for two conics associated with the curve has periodic trajectory and if and only if corresponding Pell-Abel equation has a solution
M. Poncelet, L’invention des sciences coloniales belges, Paris, Éditions Karthala, 2008, 420 p.
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