Scrambling with conservation laws

In this article we discuss the impact of conservation laws, specifically U(1) charge conservation and energy conservation, on scrambling dynamics, especially on the approach to the late time fully scrambled state. As a model, we consider a d + 1 dimensional (d ≥ 2) holographic conformal field theory with Einstein gravity dual. Using the holographic dictionary, we calculate out-of-time-order-correlators (OTOCs) that involve the conserved U(1) current operator or energy-momentum tensor. We show that these OTOCs approach their late time value as a power law in time, with a universal exponent $$ \frac{d}{2} $$ d 2 . We also generalize the result to compute OTOCs between general operators which have overlap with the conserved charges.

Impacts of Climate Change and the Need to Define an Efficient Operating Methodology for Nangbéto Dam

Climate change is a major threat to industrial development because of its adverse effects on the energy sector, especially hydroelectric power plants. This paper focuses on the analysis of the impact of climate change on the Mono River basin and the implications for the electricity production of Nangbéto Hydroelectric Power Plant. The approach consisted of combining historical hydrological data and physical, technical, and economic information to analyze the extent to which variations in average rainfall and global warming impacted the operation of the Nangbéto Hydroelectric Power plant. Based on the curves obtained, the impacts of climate change on the Mono River and on the operation of the Nangbéto Power Plant were recorded. Also, the management of the Nangbéto dam water retainer by the current operator was analyzed to highlight the strengths relating to the optimization of electricity production and the economic profitability of the plant. Keywords: Climate change, hydropower plant, optimization, hydrological data.

The quantum electrodynamics physical (QED-P) theory to complement quantum electrodynamics (QED)

The electronic and muonic hydrogen energy levels are calculated very accurately [M. L. Eides, H. Grotch, and V. Shelyuto, Phys. Rep. 342, 63 (2001)] in Quantum Electrodynamics (QED) by coupling the Dirac Equation four vector c(α, I) current covariantly with the external electromagnetic (EM) field four vector in QED’s Interactive Representation. While QED has been extraordinarily successful computationally, it presents no physical description of the electron, or other charged leptons. The QED-Physical (QED-P) theory presented in this paper is equivalent to QED in that it is based only on the four-current c(α, I) that is the reason that QED is so accurate computationally. However, QED-P describes the electron geometrically through the internal time/coordinate operators derived directly from c(α, I) with no assumptions. QED-P’s internal coordinate operators define an electron Center of Charge (CoC) point vibrating rapidly in space and time in its unique vacuum, creating the current that produces the electron’s magnetic moment and spin, and eliminating the need for “intrinsic” properties. QED-P also cuts off the photon propagator in a natural way so that the electron self-energy is finite and ad hoc renormalization procedures are not necessary. The c α-Non Exclusion Principle states that, if QED accepts c(α, I) as the electron current operator because of the very accurate hydrogen energy levels calculated, then one must also accept the QED-P electron internal spatial and time coordinate operators (ISaTCO) derived directly from c(α, I) without any other assumptions. QED-P shows the electron to be in both spin states simultaneously, and it is the external EM field that forces the electron’s spin state to be measured up or down. QED-P describes the bizarre, and very different, situation illustrated in Fig. 1 when the electron and muon are located “inside” the spatially extended proton with their CoCs orbiting the proton at the speed of light in S energy states of hydrogen, shedding some insight into the proton radius puzzle. The electron only appears to be a point particle with intrinsic properties when observed/measured from the far field. The Dirac‐Maxwell‐Wilson Equations are derived directly from the electron ISaTCO, and its EM fields “look” like they are from a point particle in far field scattering experiments in the same way the electric field from a sphere with evenly distributed charge “e” looks like a point charge with the same charge in the far field (Gauss Law). A physical basis for Quantum Entanglement is derived that can be measured experimentally.

Diffusion from convection

We introduce non-trivial contributions to diffusion constants in generic many-body systems with Hamiltonian dynamics arising from quadratic fluctuations of ballistically propagating, i.e. convective, modes. Our result is obtained by expanding the current operator in terms of powers of local and quasi-local conserved quantities. We show that only the second-order terms in this expansion carry a finite contribution to diffusive spreading. Our formalism implies that whenever there are at least two coupled modes with degenerate group velocities the system behaves super-diffusively, in accordance with non-linear fluctuating hydrodynamics. Finally, we show that our expression saturates the exact diffusion constants in quantum and classical interacting integrable systems, providing a general framework to derive these expressions.

A New Approach to Transport Coefficients in the Quantum Spin Hall Effect

We investigate some foundational issues in the quantum theory of spin transport, in the general case when the unperturbed Hamiltonian operator $$H_0$$ H 0 does not commute with the spin operator in view of Rashba interactions, as in the typical models for the quantum spin Hall effect. A gapped periodic one-particle Hamiltonian $$H_0$$ H 0 is perturbed by adding a constant electric field of intensity $$\varepsilon \ll 1$$ ε ≪ 1 in the j-th direction, and the linear response in terms of a S-current in the i-th direction is computed, where S is a generalized spin operator. We derive a general formula for the spin conductivity that covers both the choice of the conventional and of the proper spin current operator. We investigate the independence of the spin conductivity from the choice of the fundamental cell (unit cell consistency), and we isolate a subclass of discrete periodic models where the conventional and the proper S-conductivity agree, thus showing that the controversy about the choice of the spin current operator is immaterial as far as models in this class are concerned. As a consequence of the general theory, we obtain that whenever the spin is (almost) conserved, the spin conductivity is (approximately) equal to the spin-Chern number. The method relies on the characterization of a non-equilibrium almost-stationary state (NEASS), which well approximates the physical state of the system (in the sense of space-adiabatic perturbation theory) and allows moreover to compute the response of the adiabatic S-current as the trace per unit volume of the S-current operator times the NEASS. This technique can be applied in a general framework, which includes both discrete and continuum models.

Subleading contributions to the nuclear scalar isoscalar current

We extend our recent analyses of the nuclear vector, axial-vector and pseudoscalar currents and derive the leading one-loop corrections to the two-nucleon scalar current operator in the framework of chiral effective field theory using the method of unitary transformation. We also show that the scalar current operators at zero momentum transfer are directly related to the quark mass dependence of the nuclear forces.

Customer's Loyalty of Indonesia Cellular Operators in The Pandemic of COVID-1

The cellular operators business in Indonesia has significantly increased during pandemic of COVID-19 since the issuance of the government regulation regarding work from home and study from home. The increasing number of subscribers is getting higher along with the increasing high churn rate. The intention of the study was to determine the potential predictors of customer's loyalty to cellular operators. The findings show, First, user experience directly influences loyalty. Second, corporate image is revealed to strengthen the effect of user experience on switching barriers and subsequent impact on loyalty, which indicates that a good corporate image can increase customer loyalty. Third, satisfaction and switching barriers mediate the relationship between user experience and loyalty. This implies that if users perceive a good experience with their operators, they will satisfied and loyal to the current operator. In line with this situation, if there are too many barriers to switch to other operators and they believe getting value for money, they will remain loyal. The conceptual research framework proposed can be differentiated between users who perceived corporate image is high and those who perceived corporate image is low; they can be differentiated between pre-paid and post-paid cellular users. The contribution of this study lies in the fact that the path between the five dimensions of user experience to loyalty of cellular operator, the combination with the mediator of satisfaction and switching barrier to loyalty, the moderating role of corporate image which affects the direction and strengthen the relationship between user experience and switching barriers. Keywords: Cellular operators, corporate image, COVID-19, loyalty, user experience

Fishes and invertebrates of oil and gas platforms off California: an introduction and summary

This paper serves as an introduction to a symposium on the role that California oil and gas platforms serve as habitats for fishes and invertebrates. As of 2019, there are 27 platforms in state and federal waters off California, and the decommissioning of some of these platforms is imminent. Thus, consideration of whether to completely remove a platform or cut it off at some depth below the sea surface and retain the submerged portion as a reef is a decision that will occur in the near future. The objectives of the 10 papers in this dedicated issue of the Bulletin of Marine Science are to: (1) increase scientific understanding of the inter- and intrarelationships of fish and invertebrate populations at offshore oil and gas platforms and natural reefs within the Southern California Bight; (2) determine the extent of influence of platform assemblages on southern California and the Pacific coast populations of fishes and invertebrates; and (3) synthesize relevant reports, existing peer-reviewed literature, and new data analyses into a single peer-reviewed reference. This introductory paper contains a synopsis of all extant California platforms including information on: (1) the original operator, (2) the current operator of records, (3) the date the platform was installed, (4) the first production date, (5) the platform's distance from shore [including whether it is state or outer continental shelf (OCS) waters], (6) the bottom depth of the platform, (7) the number of well slots, (8) the number of conductors, (9) what the platform produces (oil and/or gas), (10) the platform jacket dimensions [generally at the seafloor (bottom)], (11) the platform's footprint, (12) the midwater surface area, (13) the total removal weight, (14) the platform location, (15) the shell mound size, (16) the shell mound volume, (17) the shell mound height, (18) the center of the shell mound location, and (19) the bottom slope. In addition, we present an overview of all previous research on the biology and ecology of California platform organisms.

A Proof of the Bloch Theorem for Lattice Models

The Bloch theorem is a powerful theorem stating that the expectation value of the U(1) current operator averaged over the entire space vanishes in large quantum systems. The theorem applies to the ground state and to the thermal equilibrium at a finite temperature, irrespective of the details of the Hamiltonian as far as all terms in the Hamiltonian are finite ranged. In this work we present a simple yet rigorous proof for general lattice models. For large but finite systems, we find that both the discussion and the conclusion are sensitive to the boundary condition one assumes: under the periodic boundary condition, one can only prove that the current expectation value is inversely proportional to the linear dimension of the system, while the current expectation value completely vanishes before taking the thermodynamic limit when the open boundary condition is imposed. We also provide simple tight-binding models that clarify the limitation of the theorem in dimensions higher than one.

Spin currents in semiconductor nanostructures: A non-equilibrium Green-function approach

This article examines spin currents and spin densities in realistic open semiconductor nanostructures using different tools of quantum-transport theory based on the non-equilibrium Green function (NEGF) approach. It begins with an introduction to the essential theoretical formalism and practical computational techniques before explaining what pure spin current is and how pure spin currents can be generated and detected. It then considers the spin-Hall effect (SHE), and especially the mesoscopic SHE, along with spin-orbit couplings in low-dimensional semiconductors. It also describes spin-current operator, spindensity, and spin accumulation in the presence of intrinsic spin-orbit couplings, as well as the NEGF approach to spin transport in multiterminal spin-orbit-coupled nanostructures. The article concludes by reviewing formal developments with examples drawn from the field of the mesoscopic SHE in low-dimensional spin-orbit-coupled semiconductor nanostructures.