Cette thèse s'attache aux rapports au politique des artistes visuels yéménites dans un contexte de domination, recouvrant trois États (les deux républiques qui précédent l'unification du Yémen et la république actuelle créée en 1990, jusqu'en 2015). En étudiant la domination en acte à travers une démarche ethnographique, ce travail interroge les conditions de production et d'action des artistes en soutien ou en contestation au régime, comme au cours du moment révolutionnaire de 2011. On observe ainsi le processus de politisation des mondes de l'art au Yémen contemporain, processus compris en tant qu'acquisition d'une signification politique par la pratique artistique et par les réseaux de relations entretenus par les artistes visuels. Ces requalifications de leur travail ou de leur pratique se font dans un contexte traversé par des luttes concurrentielles pour la répartition du pouvoir internes et propres à leurs mondes d'activité, mais aussi externes et propres à l'espace politique institutionnel. La politisation des mondes de l'art apparaît dès lors moins comme un instrument d'accès à cet espace qu'une voie pour accéder à plus de visibilité, à la reconnaissance, et à un meilleur positionnement dans les rapports agonistiques qui configurent ces mondes. / This thesis focuses on the study of Yemeni visual artists' relation to politics in a context of domination, covering three States (the two republics that precede Yemen's unification and the current republic established in 1990, until 2015). Studying domination in action through an ethnographic approach, this work questions artists' conditions of production and of action in support to or in contestation of the regime- as in the case of the revolutionary period of 2011. The focus of this study is the politicization of art worlds in contemporary Yemen, a process understood as the acquisition of a political significance as observed in the artistic practice and in the dynamic networks that artists maintain. The requalification and reclassification of their work and their practice that results from the politicization of art worlds, takes place in a context of competitive struggles over distribution and access to sites of power. Such conflict over power occurs within their own worlds of activity as well as outside them and in relation to the domain of institutional politics. This thesis contends that the politicization of art worlds is more of a means to access visibility and recognition than a resource to participate in the political field. Through the politicization of art, artists are able to better position themselves within the agonistic relations that exist within art worlds.

Cette thèse, écrite par un enseignant de judo, s’intéresse aux Professeures de judo en France. Elle relève d’abord les difficultés d’émancipation rencontrées par les femmes dans la société en général et dans le monde du sport en particulier, pour en arriver à la place des femmes dans le monde du judo, qui est un sport avant tout masculin. Les étapes de l’émancipation, du désassujétissement et de la féminisation des compétences sont ainsi abordées. On découvre la prise de conscience des enseignantes de judo de leurs qualités et la considération qu’elles ont de leur profession. Les enquêtes montrent la valeur judoïstique de ces enseignantes comme leur bon niveau d’études. La thèse démontre que les enseignantes interrogées, se répartissant entre niveau local et national, ont des conceptions, des analyses, des problématiques souvent discordantes. On remarque le fort degré d’implication de ces sportives qui ont décidé de transmettre leur passion en enseignant un sport où les résultats féminins sont probants, mais encore trop souvent masqués dans les médias par ceux des hommes. L’ensemble de la thèse s’articule donc autour de la considération apportée aux enseignantes de judo, de la considération propre que se portent ces enseignantes et du profond désir de lutter contre toute forme d’assujettissement, en démontrant qu’elles prennent progressivement conscience de leurs compétences, qui supportent aisément la comparaison avec celles de leurs homologues masculins, encore trop souvent détenteurs de tous les pouvoirs. / This thesis, written by a male judo master/coach, is about French female judo instructors. First, it deals with the difficulties facing women regarding their emancipation in society in general but also more particularly in sports, and especially their roles in the world of judo, which is predominantly male. Thus the different stages of their emancipation, their fight against submissiveness and the way in which the judo skills are becoming more and more female-oriented are discussed. The growing awareness by female judo instructors of their own skills and the regard they have for their profession are analysed. Studies have shown the quality of these female judo instructors as well as their good educational level. The thesis shows that the female instructors, ranging from local to national levels, who were questioned often have conflicting conceptions and analyses of the problems and of the ways to solve them. The high degree of involvement of these sportswomen, who have decided to share their passion through teaching a sport where the results obtained by women are convincing, but too often still concealed in the média by those of men, is noted. Central to the whole thesis is the recognition gained by female judo instructors as well as the awareness they have of their own skills and their deep desire to fight against any kind of disenfranchisement. It shows that they are progressively becoming aware of their own skills, which are easily on par with men’s, who are nevertheless still in a position of authority in the world of judo.

En France, dans une société hétéronormative à domination masculine, quelles représentations les mères lesbiennes ont-elles du genre et de la socialisation de genre de leurs enfants ? L’hypothèse principale qui sous-tend la recherche est que la position particulière des lesbiennes dans le système du genre – à la fois dominées et transfuges de la classe des femmes – leur permet un point de vue critique des normes dominantes et les prédispose à transmettre des modèles qui remettent en cause l’ordre du genre. Dans un contexte français d’institutionnalisation progressive de l’homoparentalité marqué par un débat public très houleux (2012-2013), 36 entretiens semi-directifs longs ont été réalisés entre 2011 et 2014 avec des femmes lesbiennes ayant des enfants de moins de douze ans conçus en contexte lesboparental. Malgré une certaine homogénéité des profils qui classent les enquêtées parmi les catégories sociales privilégiées, on constate une hétérogénéité des représentations et des pratiques pour composer avec les normes dominantes. Les mères lesbiennes rencontrées me semblent être des « résistantes ordinaires » à la domination : sans adhésion idéologique aux normes qui les assujettissent, elles sont animées d’une volonté d’intégration. Pragmatiques dans leur lecture du contexte et du contrat social, elles sont attentives à se préserver et à préserver leur famille des effets de l’homophobie. Elles déploient leur résistance du côté de l’infrapolitique pour repousser les limites établies par le cadre contraignant. / In the French heteronormative, male dominated society, what are French lesbian mothers’ representations of gender, and specifically of their children’s gender socialization? The main hypothesis is that being dominated as women and sex-class transfuges at the same time, lesbians have a particular position within the gender system, allowing them a critical point of view on the dominant norms. They are thus predisposed to transmit to their children gender models that challenge the gender system. In France, the gradual institutionalization of homosexual parenting is accompanied with a heated public debate (especially in 2012 and 2013). This research is primarily based on semi-structured interviews conducted between 2011 and 2014. The 36 interviewees are lesbian women with children under 12 years old, conceived within the frame of lesbian parenting. Despite the homogeneity of their social positions (middle and upper class), the interviewees have heterogeneous representations of the dominant norms. They also develop different sets of practices to face these norms. These lesbian mothers seem to develop ordinary forms of resistance to domination. While they show no ideological endorsement to heterosexist norms, they express a real will to be integrated within society. They interpret the context and social contract in a pragmatic way, and seek to protect themselves and their families from the effects of homophobia. Their resistance is mainly infra-political: pushing against the established limits of a framework that restricts them.

Vizing conjectured in 1963 that the domination number of the Cartesian product of two graphs is at least the product of their domination numbers; this remains one of the biggest open problems in the study of domination in graphs. Several partial results have been proven, but the conjecture has yet to be proven in general. The purpose of this thesis was to study Vizing's conjecture, related results, and open problems related to the conjecture. We give a survey of classes of graphs that are known to satisfy the conjecture, and of Vizing-like inequalities and conjectures for different types of domination and graph products. We also give an improvement of the Clark-Suen inequality. Some partial results about fair domination are presented, and we summarize some open problems related to Vizing's conjecture.

RESUMENotre travail s’intéresse au secteur des médias télévisés au Brésil, qui présente une forte concentration à mettre en rapport avec la domination économique et politique de certains groupes parmi les groupes de médias, comme le groupe dominant Globo. Le chapitre 1 est un chapitre introductif, qui, après avoir présenté l’économie brésilienne et le paysage médiatique au Brésil, développe la problématiqueAu cours du chapitre 2 nous avons établi une typologie des principales propriétaires des médias télévisés au Brésil, en faisant un classement des propriétaires des chaînes en familles (F), politiques (P), groupes religieux (R), état (E), global players ou majors (M), commerciales (C), chaines diverses (O). Nous étudions ensuite dans ce chapitre la concentration dans le secteur de la télévision brésilienne, suivie d’études de cas sur certains groupes de média télévisés au Brésil, dont notamment la chaîne Record News, qui appartient à Rede Record.Le chapitre 3 complète notre travail du point de vue théorique, en transposant la théorie de l’électeur médian et celle du duopole de Hotelling et en généralisant la théorie au cas d’entreprises de médias avec des contenus n-dimensionnels. Nous esquissons une application aux chaines de télévision dominantes du Brésil.Le chapitre 4 expose les résultats d’une enquête de terrain par questionnaire qui permet d’explorer la manière dont les contenus des chaînes de télévision brésilienne sont perçus par les téléspectateurs. La conclusion générale, qui fait l’objet du chapitre 5.Enfin, la thèse se termine par des annexes avec, d’une part le détail de notre questionnaire et des réponses à celui. / This work is concerned with the industry of TV media enterprises in Brazil, a sector which is highly concentrated, this concentration being related with the economic and political role of some dominant media groups, such as the Globo group. Chapter 1 deals with the introduction of our study, presenting first the economy of Brazil and the Brazilian media sector, and then developping the questions this work is concerned with.In Chapter 2, we propose to study media concentration in Brazil’s television industry; more precisely, we propose a classification of ownerships of the main TV channels, including families (F), politicians (P), religious groups (R), state and public-service companies (E), global players and majors (M), and miscellaneous ownerships (O). This is followed by a study of concentration in the TV sector based on HHI calculations since 1996, and by case studies. Chapter 3 completes our work from a theoretical economics standpoint, adapting the median voter theory and the Hotelling spatial duopoly theory to the case of media enterprises, with n-dimensional contents, and with a tentative application to dominant TV channels of Brazil.Chapter 4 deals with the results of a field questionnaire survey which enables us to have some idea of how the contents of Brazilian TV channels are received by some audiences. Chapter 5, which concludes our work, deals with a synthesis of our results, and with the research prospects it raises.Finally, our dissertation ends up with some appendixes, with, on the one hand, the detail of our questionnaire and of the results of our survey, together with some of our publications and articles related to this work.

A graph $$G$$G is diameter 2-critical if its diameter is two and the deletion of any edge increases the diameter. Murty and Simon conjectured that the number of edges in a diameter-2-critical graph G of order n is at most ⌊n2/4⌋ and that the extremal graphs are the complete bipartite graphs K⌊n/2⌋,⌈n/2⌉. We survey the progress made to date on this conjecture, concentrating mainly on recent results developed from associating the conjecture to an equivalent one involving total domination.

A graph G is diameter-2-critical if its diameter is two and the deletion of any edge increases the diameter. Murty and Simon conjectured that the number of edges in a diameter-2-critical graph G of order n is at most ⌊n2/4⌋ and that the extremal graphs are the complete bipartite graphs K⌊n/2⌋,⌈n/2⌉. A graph is t-edge-critical, abbreviated 3tEC, if its total domination number is 3 and the addition of any edge decreases the total domination number. It is known that proving the Murty–Simon Conjecture is equivalent to proving that the number of edges in a 3tEC graph of order n is greater than ⌈n(n-2)/4⌉. We study a family F of 3tEC graphs of diameter 2 for which every pair of nonadjacent vertices dominates the graph. We show that the graphs in F are precisely the bull-free 3tEC graphs and that the number of edges in such graphs is at least ⌊(n2-4)/4⌋, proving the conjecture for this family. We characterize the extremal graphs, and conjecture that this improved bound is in fact a lower bound for all 3tEC graphs of diameter 2. Finally we slightly relax the requirement in the definition of F—instead of requiring that all pairs of nonadjacent vertices dominate to requiring that only most of these pairs dominate—and prove the Murty–Simon equivalent conjecture for these 3tEC graphs.

For a graph G = (V, E), a set S ⊆ V is a total dominating set if every vertex in V is adjacent to some vertex in S. The smallest cardinality of any total dominating set is the total domination number γt(G). For an arbitrary edge e εE(Ḡ), γt(G) - 2 ≤ γt(G + e) ≤ γt(G); if the latter inequality is strict for each e ε E(Ḡ) ≠ φ, then G is said to be γt-critical. The criticality index of an edge e ε E(Ḡ) is γt(e) = γt(G) - γt(G + e). Let E(Ḡ) = [e1...,em} and S = ∑j=1m̄ci(ej). The criticality index of G is ci(G) = S/m̄. For any rational number k, 0 ≤ k ≤ 2, we construct a graph G with ci(G) = k. For 1 ≤ k ≤ 2, we construct graphs with this property that are γt-critical as well as graphs that are not γt-critical.

A set S of vertices of a graph G = (V, E) is a dominating set if every vertex in V - S is adjacent to some vertex in 3. The domination number γ(G) is the minimum cardinality of a dominating set of G, and the domination subdivision number sdγ(G) is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the domination number. In June 2000, Arumugam conjectured that 1 ≤ sdγ(G) ≤ 3 for any graph G. However, a counterexample to this conjecture given in [6] suggests the modified conjecture that 1 ≤ sdγ(G) ≤ 4 for any graph G. It is also conjectured in [6] that for every graph G with minimum degree δ(G) ≥ 2, sdγ(G) ≤ δ(G) + 1. In this paper we extend several previous results and consider evidence in support of these two conjectures.

Let G be a connected simple graph with vertex set V and a distribution of pebbles on V. The domination cover rubbling number of G is the minimum number of pebbles, so that no matter how they are distributed, it is possible that after a sequence of pebbling and rubbling moves, the set of vertices with pebbles is a dominating set of G. We begin by characterizing the graphs having small domination cover rubbling numbers and determining the domination cover rubbling number of several common graph families. We then give a bound for the domination cover rubbling number of trees and characterize the extremal trees. Finally, we give bounds for the domination cover rubbling number of graphs in terms of their domination number and characterize a family of the graphs attaining this bound.