Soft Graviton Theorem in Arbitrary Dimensions

In this note we show that the recent conjecture proposed by Cachazo and Strominger holds at tree level in arbitrary dimensions. The proof makes crucial use of the fact that the sub-leading operator is defined using the total angular momentum operator. A key ingredient that makes the proof possible is the CHY formula for graviton amplitudes in arbitrary number of dimensions.Comment: 10 page

Three-dimensional modeling of single stranded DNA hairpins for aptamer-based biosensors.

Aptamers consist of short oligonucleotides that bind specific targets. They provide advantages over antibodies, including robustness, low cost, and reusability. Their chemical structure allows the insertion of reporter molecules and surface-binding agents in specific locations, which have been recently exploited for the development of aptamer-based biosensors and direct detection strategies. Mainstream use of these devices, however, still requires significant improvements in optimization for consistency and reproducibility. DNA aptamers are more stable than their RNA counterparts for biomedical applications but have the disadvantage of lacking the wide array of computational tools for RNA structural prediction. Here, we present the first approach to predict from sequence the three-dimensional structures of single stranded (ss) DNA required for aptamer applications, focusing explicitly on ssDNA hairpins. The approach consists of a pipeline that integrates sequentially building ssDNA secondary structure from sequence, constructing equivalent 3D ssRNA models, transforming the 3D ssRNA models into ssDNA 3D structures, and refining the resulting ssDNA 3D structures. Through this pipeline, our approach faithfully predicts the representative structures available in the Nucleic Acid Database and Protein Data Bank databases. Our results, thus, open up a much-needed avenue for integrating DNA in the computational analysis and design of aptamer-based biosensors

A Conformal Collider for Holographic CFTs

We develop a formalism to study the implications of causality on OPE coefficients in conformal field theories with large central charge and a sparse spectrum of higher spin operators. The formalism has the interpretation of a new conformal collider-type experiment for these class of CFTs and hence it has the advantage of requiring knowledge only about CFT three-point functions. This is accomplished by considering the holographic null energy operator which was introduced in arXiv:1709.03597 as a generalization of the averaged null energy operator. Analyticity properties of correlators in the Regge limit imply that the holographic null energy operator is a positive operator in a subspace of the total CFT Hilbert space. Utilizing this positivity condition, we derive bounds on three-point functions $\langle TO_1O_2\rangle$ of the stress tensor with various operators for CFTs with large central charge and a sparse spectrum. After imposing these constraints, we also find that the operator product expansions of all primary operators in the Regge limit have certain universal properties. All of these results are consistent with the expectation that CFTs in this class, irrespective of their microscopic details, admit universal gravity-like holographic dual descriptions. Furthermore, this connection enables us to constrain various inflationary observables such as the amplitude of chiral gravity waves, non-gaussanity of gravity waves and tensor-to-scalar ratio.Comment: 52+15 pages, 5 figure

Einstein gravity 3-point functions from conformal field theory

We study stress tensor correlation functions in four-dimensional conformal field theories with large $N$ and a sparse spectrum. Theories in this class are expected to have local holographic duals, so effective field theory in anti-de Sitter suggests that the stress tensor sector should exhibit universal, gravity-like behavior. At the linearized level, the hallmark of locality in the emergent geometry is that stress tensor three-point functions $\langle TTT\rangle$, normally specified by three constants, should approach a universal structure controlled by a single parameter as the gap to higher spin operators is increased. We demonstrate this phenomenon by a direct CFT calculation. Stress tensor exchange, by itself, violates causality and unitarity unless the three-point functions are carefully tuned, and the unique consistent choice exactly matches the prediction of Einstein gravity. Under some assumptions about the other potential contributions, we conclude that this structure is universal, and in particular, that the anomaly coefficients satisfy $a\approx c$ as conjectured by Camanho et al. The argument is based on causality of a four-point function, with kinematics designed to probe bulk locality, and invokes the chaos bound of Maldacena, Shenker, and Stanford.Comment: 24+9 pages; minor changes, conclusions unchange

Coopération décentralisée Nord-Sud et développement territorial rural, quelle articulation? Cas des projets de tourisme rural, dans les provinces d’AZILAL et KHENIFRA

The countries of the North and South of the Mediterranean, historically interdependent due to their geostrategic position and their common interests, found themselves forced to be stand and cooperate together. This cooperation between the two shores of the Mediterranean has therefore taken a particular form of international solidarity, which has mobilized the action of local authorities involved in projects intervening in very varied fields of action through decentralized cooperation. Nevertheless, several questions have arisen concerning the impact of these actions on territorial development, especially rural territorial entities that suffer the most from poverty and marginality. To understand the issues that manipulate this type of cooperation and its impact on the development of marginal rural territories, we mobilized socio-economic indicators, mainly employment and income, as well as tourist supply and demand, within the framework of an empirical study based on the mixed method, where it was a question of evaluating and then comparing these indicators, through a questionnaire addressed to the local actors of rural tourism, at the level of two marginal rural territories endowed with considerable tourist amenities , one of which benefited from decentralized cooperation actions targeting the tourism sector. This method of evaluation allowed us to deduce that decentralized cooperation, although it intervenes through very inexpensive actions, but it can however constitute an effective form of intervention for the valorization of territorial resources and to ensure the anchoring of rural tourist activity among the local populations, who adopt it as a territorial project and make it a means of sustainable territorial development.Les pays du Nord et du Sud de la méditerranée, historiquement interdépendants de par leur position géostratégique et leurs intérêts communs, se sont trouvés contraints d’êtresolidaires et de coopérer ensemble. Cette coopération entre les deux rives méditerranéennes a pris une forme particulière de solidarité internationale, qui a mobilisé l’action des collectivités territoriales impliquées dans des projets intervenant dans des domaines d'action très variés, par le biais de la coopération décentralisée. Néanmoins, plusieurs questionnements se sont imposés, concernant l’impact de ces actions sur le développement territorial, surtout des entités territoriales rurales qui souffrent le plus de pauvreté et de marginalité. Pour appréhender les enjeux qui manipulent ce type de coopération et son impact sur le développement des territoires ruraux marginaux, on a mobilisé des indicateurs socio-économiques principalement l’emploi et le revenu, ainsi que l’offre et la demande touristiques, dans le cadre d’une étude empirique basée sur la méthode mixte, où il a été question d’évaluer puis de comparer ces indicateurs, à travers un questionnaire adressé aux acteurs locaux du tourisme rural, au niveau de deux territoires ruraux marginaux dotés d’aménités touristiques considérables, dont l’un d’eux a bénéficié des actions de coopération décentralisée ciblant le secteur touristique. Cette méthode d’évaluation nous a permis de déduire que la coopération décentralisée, malgré qu’elle intervienne à travers des actions très peu coûteuses, mais elle peut cependant constituer une forme d’intervention efficace pour la valorisation des ressources territoriales et assurer l’ancrage de l’activité touristique rurale parmi les populations locales, qui l’adoptent en tant que projet de territoire et en font un moyen de développement territorial durable.&nbsp

Synthesis, Kinetic and Catalytic Studies of Manganese Complexes with Corrole and Porphyrin Ligands

High-valent transition metal-oxo intermediates play a significant role in the catalytic cycle of the ubiquitous cytochrome P450 enzymes and in biomimetic catalytic systems. In this work, manganese(III) porphyrin and corrole systems (2) were synthesized and characterized by UV-vis absorbance and 1H-NMR, matching literaturereported spectroscopic data. Manganese(V)-oxo corroles (3) and a manganese(IV)-oxo porphyrin (4) were successfully generated by chemical oxidation using mchloroperoxybenzoic acid (m-CPBA), and their oxidation reactions with organic reductants were comparatively investigated. Results from single-turnover kinetic studies indicate that in the tris(pentafluorophenyl)corrole system (3a), the active oxidizing intermediate differs in different solvents. The active oxidizing intermediate in acetonitrile is likely the manganese(V)-oxo species 3a. However, in dichloromethane, the active oxidant is suspected to be a putative manganese(VI)-oxo species generated by disproportionation of the manganese(V)-oxo species. Tris(pentafluorophenyl)corrolato manganese(III) (2a) was shown to selectively catalyze sulfoxidation and epoxidation with iodobenzene diacetate [PhI(OAc)2] as a mild oxygen source. 2a exhibited higher conversions than triphenylcorrolato manganese(III) (2b), most likely because of the higher stability of 2a compared to 2b. In contrast, tetramesitylporphyrinato manganese(III) (2c) was more efficient in catalytic oxidations than 2a, resulting in much higher conversions, but much less selectivity. Other reported metalloporphyrin and metallocorrole systems show an accelerating effect upon addition of small amounts of water; however, neither corrole systems exhibited a positive water effect. This is attributed to the strong coordination between the manganese center and water, preventing the oxygen source from coordination