A unique Fock quantization for fields in non-stationary spacetimes

In curved spacetimes, the lack of criteria for the construction of a unique quantization is a fundamental problem undermining the significance of the predictions of quantum field theory. Inequivalent quantizations lead to different physics. Recently, however, some uniqueness results have been obtained for fields in non-stationary settings. In particular, for vacua that are invariant under the background symmetries, a unitary implementation of the classical evolution suffices to pick up a unique Fock quantization in the case of Klein-Gordon fields with time-dependent mass, propagating in a static spacetime whose spatial sections are three-spheres. In fact, the field equation can be reinterpreted as describing the propagation in a Friedmann-Robertson-Walker spacetime after a suitable scaling of the field by a function of time. For this class of fields, we prove here an even stronger result about the Fock quantization: the uniqueness persists when one allows for linear time-dependent transformations of the field in order to account for a scaling by background functions. In total, paying attention to the dynamics, there exists a preferred choice of quantum field, and only one $SO(4)$-invariant Fock representation for it that respects the standard probabilistic interpretation along the evolution. The result has relevant implications e.g. in cosmology.Comment: Typos correcte

Unitary evolution in Gowdy cosmology

Recent results on the non-unitary character of quantum time evolution in the family of Gowdy T**3 spacetimes bring the question of whether one should renounce in cosmology to the most sacred principle of unitary evolution. In this work we show that the answer is in the negative. We put forward a full nonperturbative canonical quantization of the polarized Gowdy T**3 model that implements the dynamics while preserving unitarity. We discuss possible implications of this result.Comment: 5 pages, no figures. V2 discussion expanded, references added. Final version to appear in PR

Probing doubly charged Higgs in e+e−e^+ e^- Colliders in 3-3-1 Model

The SU(3)_L\otimesU(1)_N electroweak model predicts new Higgs bosons beyond the one of the standard model. In this work we investigate the signature and production of doubly charged Higgs bosons in the $e^-e^+$ International Linear Collider and in the CERN Linear Collider. We compute the branching ratios for the doubly charged gauge bosons of the model.Comment: 17 pages, 12 figure

On the local regularity theory for the MHD equations

Local regularity results are obtained for the MHD equations using as global framework the setting of parabolic Morrey spaces. Indeed, by assuming some local boundedness assumptions (in the sense of parabolic Morrey spaces) for weak solutions of the MHD equations it is possible to obtain a gain of regularity for such solutions in the general setting of the Serrin regularity theory. This is the first step of a wider program that aims to study both local and partial regularity theories for the MHD equations

Multivoicedness as a tool for expanding school leaders’ understandings and practices for school-based professional development

This article presents findings from the implementation of a pilot study of a professional development model, Schools Inquiring and Learning with Peers (SILP) in Chile. SILP includes a network learning setting involving a cluster of three schools supported by university partners that conduct peer reviews and a school learning setting involving school teams in conversations to mobilise new leadership for learning practices. The notions of joint practice development and multivoicedness in professional conversations are the essence of these processes. Data produced through the review process, understood as voices, enabled participants to incorporate the perspectives, conceptual horizon, and intentions of administrators, students, and teachers who need to collaborate for teaching to produce learning. Across schools we observed common learning as well as important differences. These differences show that by taking an active role in making sense of their participation in a professional development programme, learners achieve outcomes that may be much more meaningful than what program designers prescribed. As facilitators we learned with participants about their specific contexts, expanding the affordances they and we envisioned for the use of new tools that became available through their participation in SILP

Ecosystem Services Linked to Water and Plant Diversity in the Igualata Paramo of Hualcanga Region

The present investigation proposes to study the ecosystem services linked to water and floristic diversity in the Igualata paramo of the Hualcanga region; 5 sampling plots of 25 m2 were installed, with 4 subplots of 1 m2. 30 samples of terrestrial vascular plants were obtained, identifying 17 botanical families, 26 genera, and 27 species, and 1 lichen and 1 moss of unidentified family and genus. It was determined that the species that stands out with the highest importance value index was Lachemilia orgiculata with 44.06%, because the species was found in 4 of the 5 study plots. In second place we have Calamagrostis intermedia species with 8.21%, while the species Vicea sp. was the species with the lowest importance value index of 0.50%, being the species with the lowest number of individuals. The Rosaceae family presented the highest index with 39.61%. The Poaceae and Asteraceae families also present dominance in this ecosystem with values of 9.63% and 5.79%, respectively. According to the Shannon index, plots P2 and P4 were those with high diversity, which corroborates with what was obtained in the Simpson index; the Sorensen index showed us that plots P4 and P5 are very similar, plots P1 and P3 are fairly similar, and the remaining plots are dissimilar, which indicated that vegetation can be found in certain areas of the investigation. The water flow supplying the resident families of the region was found to be 8.12 L/s, and its ecological flow is of 0.83 L/s, having a flow that satisfies the needs of the inhabitants. Keywords: caudal, ecological flow, ecosystem paramo, ecosystem services, floristic diverity, indices of diversity. Resumen La presente investigación propone: estudiar los servicios ecosistémicos ligados al agua y diversidad florística en el páramo del Igualata regional Hualcanga; se instalaron cinco parcelas de muestreo de 25 m2 con 4 sub parcelas de 1 m2, se obtuvo 30 muestras de plantas vasculares terrestres, identificando 17 familias botánicas, 26 géneros y 27 especies, además se colectó 1 liquen y 1 musgo de familia, género y especie no identificado. Se determinó que la especie que sobresale con mayor índice de valor de importancia fue Lachemilia orgiculata con un 44,06%, esto se debe a que la especie se encontraba en 4 de las 5 parcelas de estudio, en segundo lugar, tenemos a Calamagrostis intermedia especie con 8,21%, mientras que la especie Vicea sp. fue la que menor índice de valor de importancia presentó con un 0,50% esto se debe a que fue la especie con menor cantidad de individuos. La familia Rosaceae presentó el mayor índice con 39,61%, las familias Poaceae, y Asteraceae presentan una dominancia en este ecosistema con valores de 9,63% 5,79%, respectivamente. De acuerdo al índice de Shannon las parcelas 2 y 4 son las que poseen diversidad alta que se corrobora con lo obtenido en el índice de Simpson; en el índice de Sorensen nos muestra que las parcelas P4 vs P5 son muy similares las parcelas P1 y P3 son medianamente similares y las parcelas restantes son disimiles lo que indica que la vegetación se puede encontrar en ciertas zonas de la investigación. El caudal que posee la Regional es de 8,12 L/s, abasteciendo a las familias y su caudal ecológico es de 0,83 L/s teniendo un caudal que satisface las necesidades de los pobladores. Palabras clave: caudal, caudal ecológico, diversidad florística, ecosistema páramo, índices de diversidad, servicios ecosistémicos.&nbsp