Boundary versus bulk behavior of time-dependent correlation functions in one-dimensional quantum systems

We study the influence of reflective boundaries on time-dependent responses of one-dimensional quantum fluids at zero temperature beyond the low-energy approximation. Our analysis is based on an extension of effective mobile impurity models for nonlinear Luttinger liquids to the case of open boundary conditions. For integrable models, we show that boundary autocorrelations oscillate as a function of time with the same frequency as the corresponding bulk autocorrelations. This frequency can be identified as the band edge of elementary excitations. The amplitude of the oscillations decays as a power law with distinct exponents at the boundary and in the bulk, but boundary and bulk exponents are determined by the same coupling constant in the mobile impurity model. For nonintegrable models, we argue that the power-law decay of the oscillations is generic for autocorrelations in the bulk, but turns into an exponential decay at the boundary. Moreover, there is in general a nonuniversal shift of the boundary frequency in comparison with the band edge of bulk excitations. The predictions of our effective field theory are compared with numerical results obtained by time-dependent density matrix renormalization group (tDMRG) for both integrable and nonintegrable critical spin-$S$ chains with $S=1/2$, $1$ and $3/2$.Comment: 20 pages, 12 figure

Gravitomagnetic Moments of the Fundamental Fields

The quadratic form of the Dirac equation in a Riemann spacetime yields a gravitational gyromagnetic ratio \kappa_S = 2 for the interaction of a Dirac spinor with curvature. A gravitational gyromagnetic ratio \kappa_S = 1 is also found for the interaction of a vector field with curvature. It is shown that the Dirac equation in a curved background can be obtained as the square--root of the corresponding vector field equation only if the gravitational gyromagnetic ratios are properly taken into account.Comment: 8 pages, RevTeX Style, no figures, changed presentation -- now restricted to fields of spin 0, 1/2 and 1 -- some references adde

Non-equilibrium Statistical Mechanics of Anharmonic Crystals with Self-consistent Stochastic Reservoirs

We consider a d-dimensional crystal with an arbitrary harmonic interaction and an anharmonic on-site potential, with stochastic Langevin heat bath at each site. We develop an integral formalism for the correlation functions that is suitable for the study of their relaxation (time decay) as well as their behavior in space. Furthermore, in a perturbative analysis, for the one-dimensional system with weak coupling between the sites and small quartic anharmonicity, we investigate the steady state and show that the Fourier's law holds. We also obtain an expression for the thermal conductivity (for arbitrary next-neighbor interactions) and give the temperature profile in the steady state

Geoconservation education: the leading role of the University of Minho (Portugal)

In the University of Minho the first works concerning geoconservation were developed in 1996 in the Earth Sciences Department but it was only in 2005 that a major step was taken by this university with the creation of the master course on Geological Heritage and Geoconservation. Since that time, around 70 students were enrolled with an average of 10 new students each year. The University of Minho is also engaged with geoconservation at the PhD level. Several theses have been produced focused of themes centred in Portugal, Cape Verde and Brazil. In addition to post-graduation studies on geoconservation, there are also optional courses (5 ECTS) on geodiversity and geoconservation for the graduations on Geology, Biology and Geography. In what concerns non-formal education, the University of Minho has also some work done on raising public awareness of geoconservation through the organisation of guided fieldtrips to selected geosites, participation in TV documentaries and edition of publications

The inventory of the Portuguese geological heritage: a good example of scientific cooperation between universities

The first systematic inventory of the Portuguese geological heritage is a clear example of the academic collaboration that characterizes the geoconservation in Portugal. Three hundred and twenty six geosites with inter- national or national relevance have been inventoried under the scope of the scientific research project “Identifica- tion, characterisation and conservation of geological heritage: a geoconservation strategy for Portugal”. The geosites were selected exclusively based on their scientific value and support twenty-seven frameworks. For each geological framework a leading geoscientist from a university was responsible for the scientific characterization of the framework, to invite collaborators to identify representative geosites, and to assess the scientific value and vulnerability of the geosites. In the end, seventy geoscientists, mainly from universities, took part in the scientific results that are now important raw data to support nature conservation initiatives

Quantitative assessment of geosites with national and international relevance in Portugal: methodological procedures

During the last years geoscientists of various institutions have developed a project aiming the establishment of a geoconservation strategy in Portugal. One of the main goals of this project was the inventory of the most important Portuguese the definition of the frameworks representing the most important geological features in Portugal and considering all geodiversity. With the participation of more than seventy geoscientists, twenty-seven geological frameworks were defined according to their scientific value at both national and international levels. The scientific value together with the vulnerability was numerically assessed in order to obtain a sorted list of all geosites with scientific value. The first step geosites. The Portuguese geosites inventory will be used in nature conservation policies and land-use strategies in different levels of country's administration

Geoconservation education, research and outreach : the experience of the University of Minho (Portugal)

Geoconservation is an emerging geoscience. In order to gain recognition among the scientific community and in society in general, education lato sensu is of paramount importance. This work presents the experience of the University of Minho with geoconservation education during the past 10 years, namely with graduation and postgraduation courses, teachers training, research, and outreach. Working in those different levels enhanced the university internationalisation with an increase in students and staff exchange. In order to reinforce worldwide recognition universities should strengthen their strategy towards geoconservation by creating courses and developing research projects

Geomorphological frameworks in Portugal - a contribution for the characterzation of the geological heritage

Portugal presents a rich geodiversity in spite of its reduced area. Along 92 152 km2, the last 1000 Ma are recorded on different types of rocks. This lithological diversity together with major tectonic structures and specific Quaternary climatic conditions had developed several geomorphological features with high scientific, didactic, and aesthetic values. The concept of Geomorphological Heritage, part of what is considered Geological Heritage, has been developed by many authors during the last decade. The present work constitutes the first attempt for the definition of Portuguese geomorphological frameworks with national relevance, according to the objectives of the IAG's Geomorphological Sites Working Group and ProGEO. The emphasis is given to major landforms, with landscape value. Minor landforms and features shall be considered in the scope of a following detailed inventory and characterisation. The proposed frameworks cover all the Portuguese territory including Azores and Madeira archipelagos. For each framework some representative geosites were selected, based upon the spectacularity of the landforms, its rareness (in the Portuguese context), and essentially on its scientific and didactic values. The proposed frameworks include: i) granite landforms (Gerês and Estrela mountains); ii) carbonate and evaporite landforms (Aire and Candeeiros karsts); iii) volcanic landforms (Azores and Madeira Archipelagos); iv) residual landforms (Monsanto inselberg); v) tectonic landforms (Vilariça valley); vi) fluvial landforms as canyons (Douro) and alluvial plains (Lower Tejo); vii) coastal landforms like beaches (Quiaios-Aveiro), dunes (Porto Santo), lagoons (Obidos), estuaries (Tejo estuary), cliffs (Alentejo SW coast), and coastal platforms (Aveiro region); viii) glacial and periglacial landforms (cirques, glacial troughs, grooves, moraines and others in Estrela and Gerês mountains). Cultural landscapes are also considered, as the Alto Douro Wine Region and the Pico Island Vineyard Culture (respectively, inscribed and submitted to the World Heritage List). These examples are only indicative due to space restrictions. Until the present moment about sixty sites and areas with high geomorphological interest were considered. A significant number of those are included in protected areas, having therefore some kind of protection. Nevertheless, many others should be considered in geoconservation strategies to be implemented by Portuguese authorities

The Framework “Glacial and periglacial landforms and deposits” in the scope of the Portuguese Geological Heritage Inventory

“Geoformas, depósitos glaciários e periglaciários” é um dos contextos geológicos considerados no âmbito da inventariação em curso do património geológico em território nacional. Apesar da reduzida expressão geográfica que as geoformas, os depósitos glaciários e periglaciários têm em Portugal, é-lhes reconhecida importância científica, também por essa via e por resultarem de processos morfodinâmicos raros nas condições climáticas actualmente existentes em Portugal. Após uma avaliação de potenciais geossítios com base em critérios de valor científico, foram seleccionados dezasseis como possuindo relevância nacional.“Glacial and periglacial landforms and deposits” is one of the frameworks included in the ongoing geological heritage national inventory. The scientific value of these features is connected with the occurrence of relevant evidences of Quaternary glaciations in the higher mountains of the country like erosion landforms (U shaped valleys, cirques), depositional landforms (moraines) and deposits (subglacial tills). Sixteen geosites with national relevance were selected after a potential geosites assessment focused in scientific criteria.Este trabalho é apoiado pela Fundação para a Ciência e a Tecnologia, através do financiamento plurianual do CGUP e do projecto de investigação “Identificação, caracterização e conservação do património geológico: uma estratégia de geoconservação para Portugal” (PTDC/CTEGEX/64966/2006).info:eu-repo/semantics/publishedVersio

Promoting geodiversity in the sustainable management of nature

The diversity of nature, which includes biotic and abiotic elements, is the key for the sustainability of human society. Many people are now aware of the importance of biodiversity not only because of its intrinsic value but also in terms of ecosystem services, given its role in human well-being. The ecosystem services have been categorized in regulation, supporting, provisioning and cultural services and evaluated exclusively based on the contribution of living nature. Also national agreements and policies, including the Rio Earth Summit and UN Sustainable Development Goals, are heavily weighted to biotic nature and barely include any non-living, abiotic nature or “geodiversity” elements. Furthermore, nature conservation policy and national and regional levels (e.g. EU), usually excludes geodiversity from any effective conservation action. In fact, modern society benefits greatly from living on a geodiverse planet but this reliance is not reflected in public understanding or public policy. Using the successful model of promotion of biodiversity, the promotion of the role of geodiversity to sustainable development can be also based on “natural capital” and “ecosystem services” concepts. Geodiversity contributes to “natural capital”, defined as the “world’s stocks of natural assets, which include geology, soil, air, water and all living things”, sometimes also referred to as environmental assets that provide benefits to humanity. Geodiversity contributes to ecosystem services, based on its scientific, educational, economic, cultural, and aesthetic values. Provisioning services refers to extractable natural resources, the economic base of our modern society, which should be carefully managed. Among thousands of examples that can be presented on the importance of this service, it could be mentioned that the ubiquitous smartphone contains over half the non-radioactive elements in the periodic table, all of which are extracted from the lithosphere, a fact that the public is barely aware of. Non-extractable natural resources provide numerous benefits. Examples include the water cycle, the rock cycle, the carbon sequestration by rocks, regulation of soil erosion and regulation of natural disasters (regulating services), habitat provision, biodiversity support, platform for infrastructures (supporting services), hydrotherapy, artistic inspiration and knowledge of history and evolution of the Earth and life (cultural services). Thereby ,, non-extractable resources generate scientific, educational and economic uses (geoheritage), managed by geoconservation. In addition to geoheritage and its scientific value geoparks provide examples that address , many other benefits provided by geodiversity for human well-being. The approach to these benefits should stress the importance of the sustainable management of geodiversity. The finite character of non-renewable resources and impacts of their extraction should be always emphasized, as well as the conservation of renewable resources ensuring their sustainable use