No Riemann-hurwitz formula for the p-ranks of relative class groups

We disprove, by means of numerical examples, the existence of a Riemann-Hurwitz formula for the p-ranks of relative class groups in a p-ramified p-extension K/k of number fields of CM-type containing ?\_p. In the cyclic case of degree p, under some assumptions on the p-class group of k, we prove some properties of the Galois structure of the p-class group of K; but we have found, through numerical experimentation, that some theoretical group structures do not exist in this particular situation, and we justify this fact. Then we show, in this context, that Kida's formula on lambda invariants is valid for the p-ranks if and only if the p-class group of K is reduced to the group of ambiguous classes, which is of course not always the case.Comment: 6 pages + tables num\'erique

Stickelberger's congruences for absolute norms of relative discriminants

We give an improvement of a result of J. Martinet on Stickelberger's congruences for the absolute norms of relative discriminants of number fields, by using classical arguments of class field theory

WWW Programming using computational logic systems (and the PiLLoW/Ciao library)

We discuss from a practical point of view a number of issues involved in writing Internet and WWW applications using LP/CLP systems. We describe Pd_l_oW, a public-domain Internet and WWW programming library for LP/CLP systems which we argüe significantly simplifies the process of writing such applications. Pd_l_oW provides facilities for generating HTML structured documents, producing HTML forms, writing form handlers, accessing and parsing WWW documents, and accessing code posted at HTTP addresses. We also describe the architecture of some application classes, using a high-level model of client-server interaction, active modules. We then propose an architecture for automatic LP/CLP code downloading for local execution, using generic browsers. Finally, we also provide an overview of related work on the topic. The PiLLoW library has been developed in the context of the &- Prolog and CIAO systems, but it has been adapted to a number of popular LP/CLP systems, supporting most of its functionality

Implementing distributed concurrent constraint execution in the CIAO system

This paper describes the current prototype of the distributed CIAO system. It introduces the concepts of "teams" and "active modules" (or active objects), which conveniently encapsulate different types of functionalities desirable from a distributed system, from parallelism for achieving speedup to client-server applications. The user primitives available are presented and their implementation described. This implementation uses attributed variables and, as an example of a communication abstraction, a blackboard that follows the Linda model. Finally, the CIAO WWW interface is also briefly described. The unctionalities of the system are illustrated through examples, using the implemented primitives

I\u27ll Rise : Rememory, Hope and the Creation of a New Public Sphere In Ben Harper\u27s Music

Recent studies about resistance music in the United States primarily focus on the hip-hop movement. However, it does not offer the only musical discourse contesting contemporary injustices. Even though the debate about hip-hop is a crucial one that deserves full attention, it seems necessary to widen the current conversation on music to take into account a wider array of musical genres and artists. This will in turn allow us to see the revolutionary power of music in its full force. In the United States, black music, from the Spirituals to Rhythm and Blues, has undeniably been a potent agent for social change. Because they enable strangers to identify with each other through a common discourse, songs from many different genres have fostered what Benedict Anderson calls imagined communities

Analysis of the classical cyclotomic approach to fermat's last theorem

We give again the proof of several classical results concerning the cyclotomic approach to Fermat's last theorem using exclusively class field theory (essentially the reflection theorems), without any calculations. The fact that this is possible suggests a part of the logical inefficiency of the historical investigations. We analyze the significance of the numerous computations of the literature, to show how they are probably too local to get any proof of the theorem. However we use the derivation method of Eichler as a prerequisite for our purpose, a method which is also local but more effective. Then we propose some modest ways of study in a more diophantine context using radicals; this point of view would require further nonalgebraic investigations.Comment: Publications Math\'ematiques UFR Sciences Techniques Besan\c{c}on 2010 (2010) 85-11

Transatlantic Literary Networks during the Cold War: Emir Rodríguez Monegal, Reader for Gallimard

In this paper, I propose to address the issue of transatlantic networks and the circulation of literary paradigms between Latin America and Europe. I will focus on a relevant actor from the time of the well-known and still controversial “boom” of Latin American narrative, within the context of the Cold War (Franco 2002, Sorensen 2007, Alburquerque 2010). This was a key moment in the internationalization of Latin American writers, as José Donoso underlined in Historia personal del ‘boom’ (1972, 1983). Donoso highlighted some names that served as nodes, such as Carlos Fuentes, who played an important role, thanks to his extraordinary and natural handling of informal networks (Gras 2015). Among these names that had a specific weight in the process of international recognition of the “boom”, Donoso also highlights the figure of the Uruguayan critic Emir Rodríguez Monegal (1921–1985), to whom I will devote these pages.  I will present a very specific—and even anecdotal—example: the reading reports that Rodríguez Monegal wrote for the prestigious French publishing house Gallimard over a single year, 1967. I will also analyze the relative influence of a recognized critic in the configuration of a publisher’s catalog. This exemplifies his ability to direct, in some way, the attention of the French public to a handful of Latin American writers, based on his suggestions and proposals for translation. In doing this, I also contribute to an understanding of the decision-making mechanisms of a publisher of the magnitude of Gallimard, which led to undertaking (or not) an expensive and risky translation process

Resonant Dampers for Parametric Instabilities in Gravitational Wave Detectors

Advanced gravitational wave interferometric detectors will operate at their design sensitivity with nearly 1MW of laser power stored in the arm cavities. Such large power may lead to the uncontrolled growth of acoustic modes in the test masses due to the transfer of optical energy to the mechanical modes of the arm cavity mirrors. These parametric instabilities have the potential of significantly compromising the detector performance and control. Here we present the design of "acoustic mode dampers" that use the piezoelectric effect to reduce the coupling of optical to mechanical energy. Experimental measurements carried on an Advanced LIGO-like test mass shown a 10-fold reduction in the amplitude of several mechanical modes, thus suggesting that this technique can greatly mitigate the impact of parametric instabilities in advanced detectors