This paper aims at shedding a new light on the novelty of Poincares Methodes nouvelles de la mecanique celeste. The latters approach to the three-body-problem has often been celebrated as a starting point of chaos theory in relation to the investigat
ion of dynamical systems. Yet, the novelty of Poincares strategy can also be analyzed as having been cast out some specific algebraic practices for manipulating systems of linear equations. As the structure of a cast-iron building may be less noticeable than its creative fac{c}ade, the algebraic cast of Poincares strategy was broken out of the mold in generating the new methods of celestial mechanics. But as the various components that are mixed in some casting process can still be detected in the resulting alloy, this algebraic cast points to some collective dimensions of the Methodes nouvelles. It thus allow to analyze Poincares individual creativity in regard with the collective dimensions of some algebraic cultures. At a global scale, Poincares strategy is a testimony of the pervading influence of what used to play the role of a shared algebraic culture in the 19th century, i.e., much before the development of linear algebra as a specific discipline. This shared culture was usually identified by references to the equation to the secular inequalities in planetary theory. This form of identification highlights the long shadow of the great treatises of mechanics published at the end of the 18th century. At a more local scale, Poincares approach can be analyzed in regard with the specific evolution that Hermites algebraic theory of forms impulsed to the culture of the secular equation. Moreover, this papers shows that some specific aspects of Poincares own creativity result from a process of acculturation of the latter to Jordans practices of reductions of linear substitutions within the local algebraic culture anchored in Hermites legacy .
The legacy of Jordans canonical form on Poincares algebraic practices. This paper proposes a transversal overview on Henri Poincares early works (1878-1885). Our investigations start with a case study of a short note published by Poincare on 1884 : S
ur les nombres complexes. In the perspective of todays mathematical disciplines - especially linear algebra -, this note seems completely isolated in Poincares works. This short paper actually exemplifies that the categories used today for describing some collective organizations of knowledge fail to grasp both the collective dimensions and individual specificity of Poincares work. It also highlights the crucial and transversal role played in Poincares works by a specific algebraic practice of classification of linear groups by reducing the analytical representation of linear substitution to their Jordans canonical forms. We then analyze in detail this algebraic practice as well as the roles it plays in Poincares works. We first provide a micro-historical analysis of Poincares appropriation of Jordans approach to linear groups through the prism of the legacy of Hermites works on algebraic forms between 1879 and 1881. This mixed legacy illuminates the interrelations between all the papers published by Poincare between 1878 and 1885 ; especially between some researches on algebraic forms and the development of the theory of Fuchsian functions. Moreover, our investigation sheds new light on how the notion of group came to play a key role in Poincares approach. The present paper also offers a historical account of the statement by Jordan of his canonical form theorem. Further, we analyze how Poincare transformed this theorem by appealing to Hermites
Poincares approach to the three body problem has often been celebrated as a starting point of chaos theory in relation to the investigation of dynamical systems. Yet, Poincares strategy can also be analyzed as molded on - or casted in - some specific
algebraic practices for manipulating systems of linear equations. These practices shed new light on both the novelty and the collective dimensions of Poincares Methodes nouvelles. As the structure of a cast-iron building may be less noticeable than its creative fac{c}ade, the algebraic cast of Poincares strategy is broken out of the mold in generating the novel methods of celestial mechanics. But as the various components that are mixed in some casting process can still be detected in the resulting alloy, the algebraic cast of the Methodes nouvelles points to some collective dimensions of Poincares methods. An edited version of the present preprint is to be published in the journal textit{Lastronomie} under the title Lapproche de Poincar`E sur le problEme des trois corps. This publication is an abstract in French language of a forthcoming paper - The algebraic cast of Poincar`Es textit{M`Ethodes nouvelles} - which will develop its main claims as well as the historiographical and mathematical issues raised in section 4 and section 5.
This paper aims to provide an overview of recent researches studies on Camille Jordans early works (1860-1870). We especially shed new light on the relation between Galois and Jordan by discussing the collective dimensions of Jordans works and their receptions.
This preprint is the extended version of a paper that will be published in the proceedings of the Oberwolfach conference Explicit vs tacit knowledge in mathematics (January 2012). It presents a case study on some algebraic researches at the turn of t
he twentieth century that involved mainly French and American authors. By investigating the collective dimensions of these works, this paper sheds light on the tension between the tacit and the explicit in the ways some groups of texts hold together, thereby constituting some shared algebraic cultures. Although prominent algebraists such as Dickson made extensive references to papers published in France, and despite the roles played by algebra and arithmetic in the development of the American mathematical community, our knowledge of the circulations of knowledge between France and the United States at the beginning of the 20th century is still very limited. It is my aim to tackle such issues through the case study of a specific collective approach to finite group theory at the turn of the 20th century. This specific approach can be understood as a shared algebraic culture based on the long run circulation of some specific procedures of decompositions of the analytic forms of substitutions. In this context, the general linear group was introduced as the maximal group in which an elementary abelian group (i.e., the multiplicative group of a Galois field) is a normal subgroup.
What did algebra mean before the development of the algebraic theories of the 20th century ? This paper stresses the identities taken by the algebraic practices developped during the century long discussion around the equation around the equation of
secular inequalities (1766- 1874). In 1874, a strong controversy on the theory of bilinear and quadratic forms opposed Camille Jordan and Leopold Kronecker. The arithmetical ideal of Kronecker faced Jordans claim for the simplicity of his algebraic canonical form. As the controversy combined mathematical and historical arguments, it gave rise to the writing of a history of the methods used by Lagrange, Laplace and Weierstrass in a century long mathematical discussion around the equation of secular inequalities.
During the whole of 1874, Camille Jordan and Leopold Kronecker quar- relled vigorously over the organisation of the theory of bilinear forms. That theory promised a general and homogeneous treatment of numerous questions arising in various 19th-centu
ry theoretical contexts, and it hinged on two theorems, stated independently by Jordan and Weierstrass, that would today be considered equivalent. It was, however, the perceived difference between those two theorems that sparked the 1874 controversy. Focusing on this quarrel allows us to explore the algebraic identity of the polynomial practices of the manipulations of forms in use before the advent of structural approaches to linear algebra. The latter approaches identified these practices with methods for the classification of similar matrices. We show that the prac- tices -- Jordans canonical reduction and Kroneckers invariant computation -- reflect identities inseparable from the social context of the time. Moreover, these practices reveal not only tacit knowledge, local ways of thinking, but also -- in light of a long history tracing back to the work of Lagrange, Laplace, Cau- chy, and Hermite -- two internal philosophies regarding the significance of generality which are inseparable from two disciplinary ideals opposing algebra and arithmetic. By interrogating the cultural identities of such practices, this study aims at a deeper understanding of the history of linear algebra without focusing on issues related to the origins of theories or structures.
This paper appeals to the figure of Evariste Galois for investigating the gates between mathematics and their publics. The figure of Galois draws some lines of/within mathematics for/from the outside of mathematics and these lines in turn sketch the
silhouette of Galois as a historical figure. The present paper especially investigates the collective categories that have been used in various types of public discourses on Galoiss work (e.g. equations, groups, algebra, analysis, France, Germany etc.). In a way, this paper aims at shedding light on the boundaries some individuals drew by getting Galois his gun. It is our aim to highlight the roles of authority some individuals (such as as Picard) took on in regard with the public figure of Galois as well as the roles such authorities assigned to other individuals (such as the mediating role assigned to Jordan as a mediator between Galoiss ideas and the public). The boundary-works involved by most public references to Galois have underlying them a long-term tension between academic and public legitimacies in the definition of some models for mathematical lives (or mathematics personae)
The Jordan measure, the Jordan curve theorem, as well as the other generic references to Camille Jordans (1838-1922) achievements highlight that the latter can hardly be reduced to the great algebraist whose masterpiece, the Traite des substitutions
et des equations algebriques, unfolded the group-theoretical content of Evariste Galoiss work. The present paper appeals to the database of the reviews of the Jahrbuch uber die Fortschritte der Mathematik (1868-1942) for providing an overview of Jordans works. On the one hand, we shall especially investigate the collective dimensions in which Jordan himself inscribed his works (1860-1922). On the other hand, we shall address the issue of the collectives in which Jordans works have circulated (1860-1940). Moreover, the time-period during which Jordan has been publishing his works, i.e., 1860-1922, provides an opportunity to investigate some collective organizations of knowledge that pre-existed the development of object-oriented disciplines such as group theory (Jordan-Holder theorem), linear algebra (Jordans canonical form), topology (Jordans curve), integral theory (Jordans measure), etc. At the time when Jordan was defending his thesis in 1860, it was common to appeal to transversal organizations of knowledge, such as what the latter designated as the theory of order. When Jordan died in 1922, it was however more and more common to point to object-oriented disciplines as identifying both a corpus of specialized knowledge and the institutionalized practices of transmissions of a group of professional specialists.
