On Chow Stability for algebraic curves

In the last decades there have been introduced different concepts of stability for projective varieties. In this paper we give a natural and intrinsic criterion of the Chow, and Hilbert, stability for complex irreducible smooth projective curves $C\subset \mathbb P ^n$. Namely, if the restriction $T\mathbb P_{|C} ^n$ of the tangent bundle of $\mathbb P ^n$ to $C$ is stable then $C\subset \mathbb P ^n$ is Chow stable, and hence Hilbert stable. We apply this criterion to describe a smooth open set of the irreducible component $Hilb^{P(t),s}_{{Ch}}$ of the Hilbert scheme of $\mathbb{P} ^n$ containing the generic smooth Chow-stable curve of genus $g$ and degree $d>g+n-\left\lfloor\frac{g}{n+1}\right\rfloor.$ Moreover, we describe the quotient stack of such curves. Similar results are obtained for the locus of Hilbert stable curves.Comment: Minor corrections and improvements to presentation. We add Theorem 4.

Primordial black hole production during preheating in a chaotic inflationary model

In this paper we review the production of primordial black holes (PBHs) during preheating after a chaotic inflationary model. All relevant equations of motion are solved numerically in a modified version of HLattice, and we then calculate the mass variance to determine structure formation during preheating. It is found that production of PBHs can be a generic result of the model, even though the results seem to be sensitive to the values of the smoothing scale. We consider a constraint for overproduction of PBHs that could uncover some stress between inflation-preheating models and observations.Comment: 6 pages, 5 figures. Prepared for the conference proceedings of the 9th Mexican School on Gravitation and Mathematical Physics : Cosmology for the XXI Century: Inflation, Dark Matter and Dark Energ

Frequency correlation requirements on the biphoton wavefunction in an induced coherence experiment between separate sources

There is renewed interest in using the coherence between beams generated in separate down-converter sources for new applications in imaging, spectroscopy, microscopy and optical coherence tomography (OCT). These schemes make use of continuous wave (CW) pumping in the low parametric gain regime, which produces frequency correlations, and frequency entanglement, between signal-idler pairs generated in each single source. But can induced coherence still be observed if there is no frequency correlation, so the biphoton wavefunction is factorable? We will show that this is the case, and this might be an advantage for OCT applications. High axial resolution requires a large bandwidth. For CW pumping this requires the use of short nonlinear crystals. This is detrimental since short crystals generate small photon fluxes. We show that the use of ultrashort pump pulses allows improving axial resolution even for long crystal that produce higher photon fluxes

A Concurrency-Agnostic Protocol for Multi-Paradigm Concurrent Debugging Tools

Today's complex software systems combine high-level concurrency models. Each model is used to solve a specific set of problems. Unfortunately, debuggers support only the low-level notions of threads and shared memory, forcing developers to reason about these notions instead of the high-level concurrency models they chose. This paper proposes a concurrency-agnostic debugger protocol that decouples the debugger from the concurrency models employed by the target application. As a result, the underlying language runtime can define custom breakpoints, stepping operations, and execution events for each concurrency model it supports, and a debugger can expose them without having to be specifically adapted. We evaluated the generality of the protocol by applying it to SOMns, a Newspeak implementation, which supports a diversity of concurrency models including communicating sequential processes, communicating event loops, threads and locks, fork/join parallelism, and software transactional memory. We implemented 21 breakpoints and 20 stepping operations for these concurrency models. For none of these, the debugger needed to be changed. Furthermore, we visualize all concurrent interactions independently of a specific concurrency model. To show that tooling for a specific concurrency model is possible, we visualize actor turns and message sends separately.Comment: International Symposium on Dynamic Language

Potential for PRO in the North of Mexico: Theoretical analysis of the feasibility based in the Area Power Output

The global interest in renewable energies to substitute the fossil fuels has led to the development of new technologies and processes to obtain energy. The sources were the energy is obtained from vary, but when the resource is scarce this technologies need a different approach to make the process sustainable. In the cases of those related to water, PRO is an interesting process that could cover both requirements in places like the North of Mexico, were the amount of available water is low and the energy demand high. PRO consists in the controlled mixture of two solutions with a greater salinity were the pressurised high salinity one could be used to produce energy depressurizing it. In this work, the feasibility of implementing PRO technology in the North of Mexico is analysed. The salinities of Panuco, Soto La Marina and Mayo rivers are analysed to determine the points were the requirements for this process are fulfilled. Different reported membranes performances are compared and the best values values are tested using the information from the rivers and a modified formula for calculating water flux and area power output in PRO. The results show that analysed scenarios present a high potential for PRO applications, were under the situations analysed in this work they could reach an area power output over the minimal required to make the process feasible (5 W/m2). However, it is still necessary to design a more suitable PRO plant and a way to obtain fresh water from a shorter distance

Exploring sustainable technical alternatives for Dutch dairy systems by integrating agro-economic modelling and public preferences assessment

Theoretical discussions on the joint consideration of multiple (economic, social and environmental) functions when assessing the sustainability of human actions are increasing. However few studies exist that integrate the social demand for multifunctional agriculture in the evaluation of the sustainability and the global welfare of society. This paper presents a methodology to answer to these questions: Which are the social demands for the multiple functions of agriculture and how can they be quantified?; Which are the feasible technical alternatives of land management to satisfy these demands?; What is the value of the land use alternatives according to social preferences and which alternatives optimally satisfy the social preferences?. The net utility of alternatives for society, and therefore their sustainability, will be measured as the sum of market and non-market net changes compared to the current situation. The proposed methodology combines economic valuation, integrated modelling, stakeholder analysis, and multi-criteria evaluation. In particular, different multi-criteria methods (QFD/ANP) and agro-economic modelling and optimizing tools (Landscape IMAGES) were used. The methodology will be fully illustrated through the case study of dairy farming landscapes in the Northern Friesian Woodlands, The Netherlands. Results show that for the case study it is possible to change current farming techniques and achieve more sustainable farming systems. The more sustainable alternatives are beneficial for farmers, obtaining higher gross margin, and for government, decreasing the current levels of subsidies in agri-environmental programs. Even current environmental restrictions can be slightly relaxed without compromising social demands to the analysed Dutch dairy farming systems.Land-use planning, public preferences, agro-economic models, Environmental Economics and Policy, Livestock Production/Industries,

Multifunctional Impacts of the Olive Farming Practices in Andalusia, Spain: An Analytic Network Approach

Olive agriculture represents one of the most important economic activities in the region of Andalusia, Spain. Additionally to its economic importance the multifunctional character of agriculture and its wide territorial presence entails that it has a high potential incidence in the environmental and social dimensions of the sustainable development of the region. Despite this importance, it is hypothesised and aimed to be contrasted that olive farmers are not implementing the agricultural practices optimal from an economic, environmental and social point of view. Contrasting this hypothesis entails to evaluate with a holistic and systemic approach the multiple impacts of the different technical alternatives to diverse agricultural practices. The use of the Analytic Network Process, a Multiple Criteria Decision Analysis technique, will be illustrated as a useful approach to deal with this kind of problems characterised by complexity, lack of information and risk. The study will focus on the average yield, climatic, environmental, etc., conditions of olive cultivation in Andalusia. The results seem to confirm the initial hypothesis when comparing the current situation with different scenarios of optimal technical alternatives. In particular the technical alternatives implemented nowadays they are far from being environmentally optimal. The multifunctional benefits and the technical costs of a change from the current situation to these optimal scenarios will be analysed.Olive farming practices, Multifunctionality, Analytic Network Process, Farm Management,