Cosmological Cutting Rules

Primordial perturbations in our universe are believed to have a quantum origin, and can be described by the wavefunction of the universe (or equivalently, cosmological correlators). It follows that these observables must carry the imprint of the founding principle of quantum mechanics: unitary time evolution. Indeed, it was recently discovered that unitarity implies an infinite set of relations among tree-level wavefunction coefficients, dubbed the Cosmological Optical Theorem. Here, we show that unitarity leads to a systematic set of “Cosmological Cutting Rules” which constrain wavefunction coefficients for any number of fields and to any loop order. These rules fix the discontinuity of an n-loop diagram in terms of lower-loop diagrams and the discontinuity of tree-level diagrams in terms of tree-level diagrams with fewer external fields. Our results apply with remarkable generality, namely for arbitrary interactions of fields of any mass and any spin with a Bunch-Davies vacuum around a very general class of FLRW spacetimes. As an application, we show how one-loop corrections in the Effective Field Theory of inflation are fixed by tree-level calculations and discuss related perturbative unitarity bounds. These findings greatly extend the potential of using unitarity to bootstrap cosmological observables and to restrict the space of consistent effective field theories on curved spacetimes.

Ethnography

This chapter highlights ethnography, which is a method developed in the practice of ethnology, a subdiscipline of anthropology dedicated to the study of peoples using a micro-analytical and comparative perspective. Ethnographic methods such as immersion and micro-analysis have influenced qualitative research in sociology since the rise of the Chicago school of sociology. However, it is only since the 1970s that anthropologists have started to apply their research methods to their own societies. A founding principle of ethnographic knowledge lies in the notion of alterity and the idea that being an outsider to a culture may bring specific insights and questions about dimensions of social life that are interiorized as ‘natural’ and obvious by those native to that culture. What opened the path to ethnographizing one’s own society was the understanding that this productive and scientific use of alterity was not related to some intrinsic qualities of the researchers or the people they study, but to the ability to develop an estranged gaze, even on one’s own social world.

A questão ética e religiosa na ordem do discurso freireano

n this paper, of a bibliographic nature, the way Paulo Freire used “ethics” as the founding principle of his reflections, problematizations and arguments on the insertion of religious social work in the heart of Latin American social relations is analyzed. The following works were examined under the lens of the Archaeological Discourse Analysis, based on Foucault (2000): Cultural action for freedom, 1981 Brazilian edition; Education: the practice of freedom, 1967 Brazilian edition; Pedagogy of the oppressed, 1987 Brazilian edition; Extension or communication?, 1983 Brazilian edition; and Os cristãos e a libertação dos oprimidos, 1978 edition. It is highlighted that Paulo Freire’s understanding of ethical and religious issues does not only hold a specific way of being, as ethics works as a parameter for critical analysis of different social and historical manifestations on the religious issue and its relationship with the people. It is concluded that the meaning of the notion and the use of the signifier “ethics” as a principle of criticality is recurrent in the argument, in the positioning and in the Freirean discursive order.

From code to market: Network of developers and correlated returns of cryptocurrencies

“Code is law” is the founding principle of cryptocurrencies. The security, transferability, availability, and other properties of crypto-assets are determined by the code through which they are created. If code is open source, as is customary for cryptocurrencies, this would prevent manipulations and grant transparency to users and traders. However, this approach considers cryptocurrencies as isolated entities, neglecting possible connections between them. Here, we show that 4% of developers contribute to the code of more than one cryptocurrency and that the market reflects these cross-asset dependencies. In particular, we reveal that the first coding event linking two cryptocurrencies through a common developer leads to the synchronization of their returns. Our results identify a clear link between the collaborative development of cryptocurrencies and their market behavior. More broadly, they reveal a so-far overlooked systemic dimension for the transparency of code-based ecosystems that will be of interest for researchers, investors, and regulators.

The notion of limit in architectural theory. Two case studies in Portugal

Modern Portuguese architecture has been seen as the result of an eminently empirical and intuitive practice, dissociated from any effort of theoretical structuring. This paper intends to contradict that predominant view, presenting the notion of spatial limit as a subject that earned particular consideration from a younger, more critical and intellectually demanding generation of architects. Firstly, it introduces two notions directly related to limit - ‘extensions of the dwelling’ and ‘transition-space’ - presented in theses by Nuno Portas (b. 1934) and Pedro Vieira de Almeida (1933-2011) respectively, two highly innovative works in the academic panorama of early 1960s. Next, it focuses on the fundamental role each of the notions taken in investigative works that are parallel in time but substantially different. The first, Habitação evolutiva, is a typological study reflecting the spirit of its time by claiming the ‘right to the city’ as the founding principle of a model critical of CIAM urbanism. The second is an essay stemming from a critical reflexion on the work of an eclectic architect that eludes categorization (Raul Lino, 1879-1974) which sheds light on the need for a critical approach to the history of modern architecture.

A White Man’s War?

This chapter looks at the first two years of the Civil War, when black men were barred from serving in the US Army. It follows the debate that black Northerners conducted about the proper response to the call to serve in the US military, which they were sure would come at some point. Immediate enlistment advocates sparred with those who counseled withholding enlistment until African Americans’ demands had been met. Black Northerners began to articulate the terms under which they would serve the Union, among which citizenship emerged as central, as well as the changes necessary to bring lived reality in the United States in line with the founding principle of equality.

The (Mis)framing of Arab Commercial Adjudication: The Sharīʿah, Political Contestation, and Due Process

This article argues that the claims that international commercial adjudication is inconsistent with Islamic law, or, in the Arab context, is born out of the 20th century petroleum concession disputes, are unfounded. First, the early Arab-Islamic trade interactions, in their multicultural and legal contexts, established transnational commercial adjudication. These interactions were facilitated by flexible Islamic regulations regarding free trade and adjudication, especially the freedom to arbitrate. Second, there have been profound international and inter-Arab political contestations since the 1950s that have affected international arbitration. These contestations could render the petroleum disputes irrelevant to the evolution of Arab commercial adjudication and foreign investment arbitration. However, international arbitration can be traced back to the principle of due process of law beyond the State; the perceived founding principle of Arab commercial adjudication. Recognising this history is important for researchers to assess the successes and flaws of arbitral due process in the Arab context.

The Jouissance of Language, or Lacan’s Ab-Aristotelianism

This chapter looks at the various negations involved in the “other” of meaning, beyond the philosophically comfortable couple sense/nonsense(Freud’s analysis of jokes as the Unsinn in Sinn), and toward a theorization ofsomething closer to Lacan’s real, as “ab-sense.”This underscores the importance of lack as a foundation of desire—Lacan’s famous dictum “there is no such thing as a sexual relationship”—and as a founding principle of “otherness” within language and between languages. A reading of a passage in Democritus points to the way in which this radical otherness of language undermines the very foundation of materialist physics, just as Lacan undermines rationalist models of contemporary science.This in turn becomes a meditation on the nature of feminine sexuality and jouissance, particularly in Lacan’s most important seminar devoted to this question, Encore.