Hall conductance and the statistics of flux insertions in gapped interacting lattice systems

We study charge transport for zero-temperature infinite-volume gapped lattice systems in two dimensions with short-range interactions. We show that the Hall conductance is locally computable and is the same for all systems that are in the same gapped phase. We provide a rigorous version of Laughlin’s flux-insertion argument, which shows that for short-range entangled systems, the Hall conductance is an integer multiple of e²/h. We show that the Hall conductance determines the statistics of flux insertions. For bosonic short-range entangled systems, this implies that the Hall conductance is an even multiple of e²/h. Finally, we adapt a proof of quantization of the Thouless charge pump to the case of infinite-volume gapped lattice systems in one dimension

Hall conductance and the statistics of flux insertions in gapped interacting lattice systems

We study charge transport for zero-temperature infinite-volume gapped lattice systems in two dimensions with short-range interactions. We show that the Hall conductance is locally computable and is the same for all systems which are in the same gapped phase. We provide a rigorous versions of Laughlin's flux-insertion argument which shows that for short-range entangled systems the Hall conductance is an integer multiple of e^2/h. We show that the Hall conductance determines the statistics of flux insertions. For bosonic short-range entangled systems, this implies that the Hall conductance is an even multiple of e^2/h. Finally, we adapt a proof of quantization of the Thouless charge pump to the case of infinite-volume gapped lattice systems in one dimension.Comment: 35 pages. v2: some arguments in Section 4.3 have been corrected and moved to an appendix. Version accepted for publication in Journal of Mathematical Physics. v3: a comment added at the end of Section 4.3, typos in Appendix C fixe

A long-term outlook on Russian oil industry facing internal and external challenges

International audienceRussian petroleum industry plays a vital part in both the country’s economy and international hydrocarbon market, providing a third of state budget revenues and over 13% of global liquid hydrocarbon exports. Yet, nowadays the industry is facing a number of serious challenges, which threaten to undermine its sustainability. These challenges include depletion of the conventional oil resources, technological and economic sanctions and stagnating demand for liquid fuels, especially apparent in Russian traditional export destinations – Europe. The authors attempted to evaluate the impact of these issues and compile a forecast of Russian oil industry using state-of-the-art modelling tools. The calculations show, that even under fairly negative scenario assumptions, Russia is capable of maintaining crude oil and refined products exports above 250 mtoe up to 2040, remaining the world’s second liquid hydrocarbon supplier. This, however, is still a huge drop from 425 mtoe of exports in 2018. To ensure sustainability the government and oil companies need to work in conjunction in several fields: facilitate geologic survey of conventional and promising oil and gas basins; domestic development of new oil extraction technologies for accessing unconventional and low-margin oil resources; provide transport infrastructure for remote fields; reforming tax system to better suit the new environment. This way, crude production can be maintained above 500 mtoe in the forecast period and exports even surpass 2018 levels. In any case, however, the need for massive investments and tax incentives coupled with global movement away from fossil fuels means, that in the future oil will be becoming less and less profitable for the state budget, thus Russian government needs to redouble efforts on economic diversification and energy transition

Rapid Cycling and Exceptional Yield in a Metal-Organic Framework Water Harvester.

Sorbent-assisted water harvesting from air represents an attractive way to address water scarcity in arid climates. Hitherto, sorbents developed for this technology have exclusively been designed to perform one water harvesting cycle (WHC) per day, but the productivities attained with this approach cannot reasonably meet the rising demand for drinking water. This work shows that a microporous aluminum-based metal-organic framework, MOF-303, can perform an adsorption-desorption cycle within minutes under a mild temperature swing, which opens the way for high-productivity water harvesting through rapid, continuous WHCs. Additionally, the favorable dynamic water sorption properties of MOF-303 allow it to outperform other commercial sorbents displaying excellent steady-state characteristics under similar experimental conditions. Finally, these findings are implemented in a new water harvester capable of generating 1.3 L kgMOF -1 day-1 in an indoor arid environment (32% relative humidity, 27 °C) and 0.7 L kgMOF -1 day-1 in the Mojave Desert (in conditions as extreme as 10% RH, 27 °C), representing an improvement by 1 order of magnitude over previously reported devices. This study demonstrates that creating sorbents capable of rapid water sorption dynamics, rather than merely focusing on high water capacities, is crucial to reach water production on a scale matching human consumption

New solutions to the Reflection Equation and the projecting method

New integrable boundary conditions for integrable quantum systems can be constructed by tuning of scattering phases due to reflection at a boundary and an adjacent impurity and subsequent projection onto sub-spaces. We illustrate this mechanism by considering a gl(m<n)-impurity attached to an open gl(n)-invariant quantum chain and a Kondo spin S coupled to the supersymmetric t-J model.Comment: Latex2e, no figure

The Omega Deformation, Branes, Integrability, and Liouville Theory

We reformulate the Omega-deformation of four-dimensional gauge theory in a way that is valid away from fixed points of the associated group action. We use this reformulation together with the theory of coisotropic A-branes to explain recent results linking the Omega-deformation to integrable Hamiltonian systems in one direction and Liouville theory of two-dimensional conformal field theory in another direction.Comment: 96 p

Multiloop Superstring Amplitudes from Non-Minimal Pure Spinor Formalism

Using the non-minimal version of the pure spinor formalism, manifestly super-Poincare covariant superstring scattering amplitudes can be computed as in topological string theory without the need of picture-changing operators. The only subtlety comes from regularizing the functional integral over the pure spinor ghosts. In this paper, it is shown how to regularize this functional integral in a BRST-invariant manner, allowing the computation of arbitrary multiloop amplitudes. The regularization method simplifies for scattering amplitudes which contribute to ten-dimensional F-terms, i.e. terms in the ten-dimensional superspace action which do not involve integration over the maximum number of $\theta$'s.Comment: 23 pages harvmac, added acknowledgemen

Evaluation of long-term production capacity and prospects of the oil and gas industry of Russian Federation

The importance of oil and gas industry for Russia is hard to overestimate. Continued leadership in hydrocarbon production and exports are cornerstones for Russian economic and political prowess as well as energy and social security. The key to sustainability of oil and gas production is, first and foremost, the resource base. In this study the authors attempted to analyze production capacity of the contemporary hydrocarbon production projects, both brownfield and greenfield, using the Hubbert linearization approach. The development of several major greenfields and the successful production maintenance at the developed fields provided Russia with record levels of production, even compared to the period of the USSR and created a potential for further production growth up to 2020. However, by 2025 this potential will be exhausted and only tapping into hard-to-recover reserves and Bazhen formation will be able to slow down the inevitable decline in production. This, however, will largely depend on active domestic development of new production technologies. The situation in the gas industry appears more favorable. Massive reserves of conventional gas, primarily in the Yamal Peninsula, provide the means to increasing annual production to over 1 trillion cubic meters. At the same time, even such a base of new reserves is not capable of completely replacing the phasing out of giant deposits of Nadym-Pur-Taz, which leads to the subsidence of production capacity beyond 2035 and the need to develop new and more complex resources