Higher Auslander-Reiten sequences and tt-structures

Let $R$ be an artin algebra and $\mathcal{C}$ an additive subcategory of $\operatorname{mod}(R)$. We construct a $t$-structure on the homotopy category $\operatorname{K}^{-}(\mathcal{C})$ whose heart $\mathcal{H}_{\mathcal{C}}$ is a natural domain for higher Auslander-Reiten (AR) theory. The abelian categories $\mathcal{H}_{\operatorname{mod}(R)}$ (which is the natural domain for classical AR theory) and $\mathcal{H}_{\mathcal{C}}$ interact via various functors. If $\mathcal{C}$ is functorially finite then $\mathcal{H}_{\mathcal{C}}$ is a quotient category of $\mathcal{H}_{\operatorname{mod}(R)}$. We illustrate the theory with two examples: Iyama developed a higher AR theory when $\mathcal{C}$ is a maximal $n$-orthogonal subcategory, see \cite{I}. In this case we show that the simple objects of $\mathcal{H}_{\mathcal{C}}$ correspond to Iyama's higher AR sequences and derive his higher AR duality from the existence of a Serre functor on the derived category $\operatorname{D}^b(\mathcal{H}_{\mathcal{C}})$. The category $\mathcal{O}$ of a complex semi-simple Lie algebra $\mathfrak{g}$ fits into higher AR theory by considering $R$ to be the coinvariant algebra of the Weyl group of $\mathfrak{g}$.Comment: 26 pages, accepted for publication in Journal of Algebra 201

The credit supply channel of monetary policy: evidence from a FAVAR model with sign restrictions

We test whether the credit channel of the monetary policy was present in the United States' economy from January 2001 to April 2016. To this end, we use a factor-augmented vector autoregression, and we impose sensible theoretical sign restrictions in our structural identification scheme. We use the expected substitution effect between bank commercial loans and commercial papers to identify the credit supply channel. We found that the credit channel appears to have operated in the US economy during the sample period. However, when we split the sample, we found that the credit channel did not operate after the subprime crisis (close to the Zero Lower Bound of the interest rate). This result is robust to changing the sign restriction horizons. It supports current views in the literature regarding the ineffectiveness of the credit channel as a means to foster real economic activity during crises episodes

When War Adversaries Talk: The Experimental Effect of Engagement Rules on Postconflict Deliberation

A set of discussion groups including leftist ex-guerrillas and rightist ex-paramilitaries in Colombia shows the limits for democratic deliberation in postconflict societies, but also points to ways that outcomes closer to the deliberative ideal might be obtained. A total of 342 ex-combatants agreed to sit down and talk politics under a number of experimental conditions, using three different protocols of engagement. Results show that consensus rule fosters simultaneously a more reasoned and common-good–oriented, and less self-interested type of discussion when compared to majority rule and unstructured “free talk.” Nevertheless, while it might be desirable to promote a better quality of deliberation in divided societies, it does not necessarily prevent antagonists’ tendency to polarize. © 2016 University of Miam

Characterization of Extended Uncertainty Principle Black Holes

Black Holes are special objects as they are at the intersection of Quantum Mechanics and General Relativity. A central tenant of quantum mechanics is the Uncertainty Principle that dictates we cannot know with complete certainty position and momentum at the same time. The Extended Uncertainty Principle introduces a position-related uncertainty correction L_* to account for General Relativity. In a previous paper, a black hole metric associated with the Extended Uncertainty Principle was derived, by modifying the metric function of a Schwarzschild black hole. This metric introduces near-horizon structures that should produce observable effects, such as love numbers, gravitational wave echoes, quasi-normal modes, and absorption coefficients. Some of these effects could be observed with current or near-term technology such as the Laser Interferometer Gravitational Wave Observatory (LIGO) and the Event Horizon Telescope (EHT). Other than calculating the expected value of the aforementioned observables, this article discusses the magnitude of L_*

Neutrino oscillations within the induced gravitational collapse paradigm of long gamma-ray bursts

The specific class of binary-driven hypernovae within the induced gravitational collapse scenario for the explanation of the long Gamma-Ray Bursts indicates as progenitor a binary system composed of a carbon-oxygen core and a neutron star in a tight orbit. The supernova explosion of the core triggers a hypercritical (highly super-Eddington) accretion process onto the NS companion, making it reach the critical mass with consequent formation of a Kerr black hole. Recent numerical simulations of the above system show that a part of the ejecta keeps bound to the newborn Kerr black hole with enough angular momentum to generate a new process of hypercritical accretion, i.e. an accretion disk. Throughout this entire process, we focus on two contexts of neutrino emission leading to two different systems in which an analysis of neutrino flavour oscillations (or flavour transformations) not only constitutes a novel extension of the induced gravitational collapse paradigm literature but also can have an impact on a wide range of astrophysical phenomena: from $e^{-}e^{+}$ plasma production in the vicinity of neutron stars or black holes in GRB models, to r-process nucleosynthesis in disk winds and characterization of astrophysical MeV neutrino sources. In particular, we study neutrino oscillations in: egin{enumerate} - extit{Spherical accretion onto a neutron star:} During this process, copious amounts of neutrino--anti-neutrino pairs ($uar{ u}$) are emitted at the neutron star surface. The neutrino emission can reach luminosities of up to $10^{57}$~MeV~s$^{-1}$, mean neutrino energies 20~MeV, and neutrino densities $10^{31}$~cm$^{-3}$. Along their path from the vicinity of the NS surface outward, such neutrinos experience flavour transformations dictated by the neutrino to electron density ratio. We determine the neutrino and electron on the accretion zone and use them to compute the neutrino flavour evolution. For normal and inverted neutrino-mass hierarchies and within the two-flavour formalism ($u_{e} u_{x}$), we estimate the final electronic and non-electronic neutrino content after two oscillation processes: (1) neutrino collective effects due to neutrino self-interactions where the neutrino density dominates and, (2) the Mikheyev-Smirnov-Wolfenstein effect, where the electron density dominates. We find that the final neutrino content is composed by $sim$55% ($sim$62%) of electronic neutrinos, i.e. $u_{e}+ar{ u}_{e}$, for the normal (inverted) neutrino-mass hierarchy. - extit{Neutrino-cooled disks around a Kerr black hole:} In this phase of the binary-driven hypernovae, given the extreme conditions of high density (up to $10^{12}$~g~cm$^{-3}$) and temperatures (up to tens of MeV) inside this disk, neutrinos can reach densities of $10^{33}$~cm$^{-3}$ and energies of $50$~MeV. Although the geometry of the disk is significantly different from that of spherical accretion, these conditions provide an environment that allows neutrino flavour transformations. We estimate the evolution of the electronic and non-electronic neutrino content within the two-flavour formalism ($u_{e} u_{x}$) under the action of neutrino collective effects by neutrino self-interactions. We find that neutrino oscillations inside the disk can have frequencies between $sim (10^{5}$--$10^{9})$~s$^{-1}$, leading the disk to achieve flavour equipartition. This implies that the energy deposition rate by neutrino annihilation ($u + ar{ u} o e^{-} + e^{+}$) in the vicinity of the Kerr black hole is smaller than previous estimates in the literature not accounting by flavour oscillations inside the disk. The exact value of the reduction factor depends on the $u_{e}$ and $u_{x}$ optical depths but it can be as high as $sim 5$. This work has allowed us to identify key theoretical and numerical features involved in the study of neutrino oscillations and our results are a first step toward the analysis of neutrino oscillations in unique astrophysical settings other than core-collapse supernovae. As such, they deserve further attention

Huertos, diversidad y alimentación en una zona de transición ecológica del estado de México

The study of the home gardens in Mexico is important. It represents an alternative food supplement of the families in rural and urban zones. In the zone ecological transitional State of Mexico the diversity of vegetal species in the home gardens is wide, due to the interaction of geographic, climatic, soil, environmental and ecological conditions. The products obtained have diverse uses: nutritional, social, ritual and commercial, being the most important that for subsistence and the social relation

Auxiliary Companies of the Horticultural Sector as a Competitiveness Element: The Case of Almeria (Spain)

The horticultural model of Almeria (Spain) based on the operation of greenhouses is an international reference and has been considered as an economic miracle. Alongside this agricultural development has been the deployment of the diverse productive activity of auxiliary companies. The objective of this article is to understand how these companies operate and analyze their factors of competitiveness, competing needs, and future competitive improvements, taking as reference four of the most important subsectors (machinery, greenhouse infrastructure, plastics, and seeds). The Delphi method was used and through a panel of experts the conditioning factors of each of the variables to be analyzed (factors, needs, and competitiveness improvements) was chosen. Of the 120 companies that were sent questionnaires, 72 participated. The sectors that make up the auxiliary companies are heterogeneous and therefore the results obtained have differed among them. The synergies between the greenhouse crops and the auxiliary companies are an example of diversification of productive activity that can be extrapolated to other production areas worldwide. The future of the auxiliary companies is linked to that of the intensive agriculture and the key variables must be underscored by competitiveness and sustainability