Effective Average Action in N=1 Super-Yang-Mills Theory

For N=1 Super-Yang-Mills theory we generalize the effective average action Gamma_k in a manifest supersymmetric way using the superspace formalism. The exact evolution equation for Gamma_k is derived and, introducing as an application a simple truncation, the standard one-loop beta-function of N=1 SYM theory is obtained.Comment: 17 pages, LaTeX, some remarks added, misprints corrected, to appear in Phys. Rev.

Orto Botanico di Siena: centro di biodiversità per la comunità

La storia del Museo Botanico attraverso gli anni conferma l’impronta dell’istituzione universitaria: insegnare, ricercare/coltivare e passare la conoscenza a pubblico/studenti. Un Giardino dei Semplici nel 1684, poi un Orto Botanico dal 1856 e dagli anni 2000 un Centro di conservazione e studio della biodiversità locale. Questa è, nella città del palio, l’immagine dell’Orto Botanico, che sta lavorando con pubblici diversi e vuole trovare una nuova dimensione all’interno della comunità cittadina, per svolgere la sua missione di centro culturale, di spazio verde nella città per svago e piacere, ma allo stesso tempo di luogo di comunicazione scientifica.The history of the Botanical Museum through the years confirms the imprint of the university institution: teaching, researching/cultivating and passing on knowledge to the public/students. A Giardino dei Semplici in 1684, then a Botanical Garden from 1856 and since the 2000s a Centre for the conservation and study of local biodiversity. This is the image of the Botanical Garden in the city of the Palio, which is working with different audiences and wants to find a new dimension within the city community, to carry out its mission as a cultural centre, a green space in the city for recreation and pleasure, but at the same time a place for scientific communication

Hard Non-commutative Loops Resummation

The non-commutative version of the euclidean $g^2\phi^4$ theory is considered. By using Wilsonian flow equations the ultraviolet renormalizability can be proved to all orders in perturbation theory. On the other hand, the infrared sector cannot be treated perturbatively and requires a resummation of the leading divergencies in the two-point function. This is analogous to what is done in the Hard Thermal Loops resummation of finite temperature field theory. Next-to-leading order corrections to the self-energy are computed, resulting in $O(g^3)$ contributions in the massless case, and $O(g^6\log g^2)$ in the massive one.Comment: 4 pages, 3 figures. The resummation procedure is now discussed also at finite ultraviolet cut-off. Minor changes in abstract and references. Final version to be published in Physical Review Letter

First record of Toxodontidae (Mammalia, Notoungulata) from the late Miocene - Early Pliocene of the southern central Andes, NW Argentina

A new species of toxodontid notoungulate, Xotodon maimarensis n. sp., is described from the Maimará Formation (late Miocene - early Pliocene), Jujuy Province, northwestern Argentina. This is the first record of a toxodontid from the Eastern Cordillera. The specimen is housed at the Museo de Geología, Mineralogía y Paleontología, Instituto de Geología y Minería de la Universidad Nacional de Jujuy. It consists of an incomplete mandible preserving the right mandibular ramus with part of the dental series, partially preserved symphysis with all the incisors, and a small portion of the left ramus without teeth. The following characters distinguish it as a new taxon: symphysis long and narrow with slight divergence of its lateral borders; strong procumbence of lower incisors and deeply implanted i3; chin angle lower than in X. major and X. cristatus and bulging labial keel limiting strong lateral concavities. Comparative analysis in the context of the recently revised Neogene Toxodontidae indicates that the Maimará specimen shares mandibular features and dental characters with Xotodon and Mixotoxodon, differing from the latter by the more upraised symphysis. The phylogenetic position of Xotodon maimarensis n. sp. supports the taxonomic interpretation of the studied specimen as a new species of Xotodon. This new Toxodontidae increases the knowledge of the diversity and radiation of this group of notoungulates in northwest Argentina.Facultad de Ciencias Naturales y Muse

Contribution to the bryological knowledge of the Tuscan-Emilian Apennines (Northern Italy)

The inventory of the bryophytes collected during the annual excursion of the Working Group for Bryology of the Italian Botanical Society is reported. This excursion was held in 2018 on the northern slope of the Tuscan-Emilian Apennines National Park, in the Administrative Region of Emilia-Romagna. The field work led to the finding of 113 taxa (24 liverworts and 89 mosses), including eight new records and seven confirmations for this Region. The occurrence of rare taxa for Italy (Scapania uliginosa, Rhizomnium pseudopunctatum, Racomitrium fasciculare, Scorpidium cossonii, Grimmia lisae, Orthotrichum pulchellum) is highlighted

Two loop results from one loop computations and non perturbative solutions of exact evolution equations

A nonperturbative method is proposed for the approximative solution of the exact evolution equation which describes the scale dependence of the effective average action. It consists of a combination of exact evolution equations for independent couplings with renormalization group improved one loop expressions of secondary couplings. Our method is illustrated by an example: We compute the beta-function of the quartic coupling lambda of an O(N) symmetric scalar field theory to order lambda^3 as well as the anomalous dimension to order lambda^2 using only one loop expressions and find agreement with the two loop perturbation theory. We also treat the case of very strong coupling and confirm the existence of a "triviality bound".Comment: 32 pages, HD-THEP-94-3, replaced because: lines too long, blank line

Renormalization of the Hamiltonian and a geometric interpretation of asymptotic freedom

Using a novel approach to renormalization in the Hamiltonian formalism, we study the connection between asymptotic freedom and the renormalization group flow of the configuration space metric. It is argued that in asymptotically free theories the effective distance between configuration decreases as high momentum modes are integrated out.Comment: 22 pages, LaTeX, no figures; final version accepted in Phys.Rev.D; added reference and appendix with comment on solution of eq. (9) in the tex

Updated data on Litopterna from the Huayquerian Stage/Age (Late Miocene-Early Pliocene) of central-east Argentina

Hitherto, only the Proterotheriidae Ameghino, 1887 litopterns from the Cerro Azul Formation (Chasicoan-Huayquerian Stages/Ages; Late Miocene-Early Pliocene) in La Pampa Province had been studied, recognizing Proterotheriidae indet. at Cerro La Bota, Diplasiotherium pampa Soria, 2001 at several localities, Eoauchenia primitiva Ameghino, 1887 at El Guanaco, and cf. Brachytherium cuspidatum Ameghino, 1883 at Salinas Grandes de Hidalgo, which added to Epecuenia thoatherioides Cabrera, 1939 from Laguna Epecuén in Buenos Aires Province; this locality also yielded the Macraucheniidae Gervais, 1855 Huayqueriana cristata (Rovereto, 1914). Now, we enlarge the study to both litoptern families and to the outcrops of the Cerro Azul Formation in Buenos Aires Province. Concerning Macraucheniidae, we recognize: Scalabrinitherium bravardi Ameghino, 1883 at Salinas Grandes de Hidalgo, Telén, and Guatraché (La Pampa), and Laguna Epecuén (Buenos Aires); Paranauchenia denticulata Ameghino, 1891, Promacrauchenia sp., and Cullinia sp. at Salinas Grandes de Hidalgo and Laguna Chillhué (La Pampa); cf. Oxyodontherium zeballosi Ameghino, 1883b at Laguna del Monte (Buenos Aires); and Promacrauchenia sp. at Cantera Relleno Sanitario (Buenos Aires). Referring to Proterotheriidae, new results reveal the first record of Diplasiotherium pampa in Buenos Aires (Arroyo El Venado) and Neobrachytherium sp. at Laguna Epecuén and Laguna La Paraguaya (Buenos Aires). The litoptern diversity is close to that from the Lower Member of the Ituzaingó Formation, Late Miocene, Entre Ríos Province. The litoptern record does not provide confident data to support or reject the established relative biostratigraphic succession of localities of the Cerro Azul Formation, which is mainly based on some rodent lineages.Fil: Schmidt, Gabriela Ines. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Montalvo, Claudia I.. Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Cerdeño Serrano, Maria Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Sostillo, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Tomassini, Rodrigo Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; ArgentinaFil: Bonini, Ricardo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; Argentin

Nonperturbative Evolution Equation for Quantum Gravity

A scale--dependent effective action for gravity is introduced and an exact nonperturbative evolution equation is derived which governs its renormalization group flow. It is invariant under general coordinate transformations and satisfies modified BRS Ward--Identities. The evolution equation is solved for a simple truncation of the space of actions. In 2+epsilon dimensions, nonperturbative corrections to the beta--function of Newton's constant are derived and its dependence on the cosmological constant is investigated. In 4 dimensions, Einstein gravity is found to be ``antiscreening'', i.e., Newton's constant increases at large distances.Comment: 35 pages, late