19,081 research outputs found

    Resource Wealth, Innovation and Growth in the Global Economy

    Get PDF
    We analyze the relative growth performance of open economies in a two-country model where different endowments of labor and a natural resource generate asymmetric trade. A resource-rich economy trades resource-based intermediates for final manufacturing goods produced by a resource-poor economy. Productivity growth in both countries is driven by endogenous innovations. The effects of a sudden increase in the resource endowment depend crucially on the elasticity of substitution between resources and labor in interme- diates' production. Under substitution (complementarity), the resource boom generates higher (lower) resource income, lower (higher) employment in the resource-intensive sector, higher (lower) knowledge creation and faster (slower) growth in the resource-rich economy. The resource-poor economy adjusts to the shock by raising (reducing) the relative wage, and experiences a positive (negative) growth effect that is exclusively due to trade.Endogenous Growth, Endogenous Technological Change, Natural Resources, International Trade.

    Growth on a Finite Planet: Resources, Technology and Population in the Long Run

    Get PDF
    We study the interactions between technological change, resource scarcity and population dynamics in a Schumpeterian model with endogenous fertility. There exists a pseudo- Malthusian equilibrium in which population is constant and income grows exponentially: the equilibrium population level is determined by resource scarcity but is independent of technology. The stability properties are driven by (i) the income reaction to increased resource scarcity and (ii) the fertility response to income dynamics. If labor and resources are substitutes in production, income and fertility dynamics are self-balancing and the pseudo-Malthusian equilibrium is the global attractor of the system. If labor and resources are complements, income and fertility dynamics are self-reinforcing and drive the economy towards either demographic explosion or human extinction. Introducing a minimum resource requirement, we obtain a second steady state implying constant population even under complementarity. The standard result of exponential population growth appears as a rather special case of our model.Endogenous Innovation, Resource Scarcity, Population Growth, Fertility Choices

    Dynamically localized systems: entanglement exponential sensitivity and efficient quantum simulations

    Full text link
    We study the pairwise entanglement present in a quantum computer that simulates a dynamically localized system. We show that the concurrence is exponentially sensitive to changes in the Hamiltonian of the simulated system. Moreover, concurrence is exponentially sensitive to the ``logic'' position of the qubits chosen. These sensitivities could be experimentally checked efficiently by means of quantum simulations with less than ten qubits. We also show that the feasibility of efficient quantum simulations is deeply connected to the dynamical regime of the simulated system.Comment: 5 pages, 6 figure

    unWISE tomography of Planck CMB lensing

    Full text link
    MB lensing tomography, or the cross-correlation between CMB lensing maps and large-scale structure tracers over a well-defined redshift range, has the potential to map the amplitude and growth of structure over cosmic time, provide some of the most stringent tests of gravity, and break important degeneracies between cosmological parameters. In this work, we use the unWISE galaxy catalog to provide three samples at median redshifts z∼0.6,1.1z \sim 0.6, 1.1 and 1.5, fully spanning the Dark Energy dominated era, together with the most recent Planck CMB lensing maps. We obtain a combined cross-correlation significance S/N=79.3S/N = 79.3 over the range of scales 100<ℓ<1000100 < \ell < 1000. We measure the redshift distribution of unWISE sources by a combination of cross-matching with the COSMOS photometric catalog and cross-correlation with BOSS galaxies and quasars and eBOSS quasars. We also show that magnification bias must be included in our analysis and perform a number of null tests. In a companion paper, we explore the derived cosmological parameters by modeling the non-linearities and propagating the redshift distribution uncertainties.Comment: 51 pages, 22 figures. Comments welcome! Revisions reflect version accepted by JCA

    Discontinuous Galerkin approximation of linear parabolic problems with dynamic boundary conditions

    Full text link
    In this paper we propose and analyze a Discontinuous Galerkin method for a linear parabolic problem with dynamic boundary conditions. We present the formulation and prove stability and optimal a priori error estimates for the fully discrete scheme. More precisely, using polynomials of degree p≥1p\geq 1 on meshes with granularity hh along with a backward Euler time-stepping scheme with time-step Δt\Delta t, we prove that the fully-discrete solution is bounded by the data and it converges, in a suitable (mesh-dependent) energy norm, to the exact solution with optimal order hp+Δth^p + \Delta t. The sharpness of the theoretical estimates are verified through several numerical experiments

    Network recovery after massive failures

    Get PDF
    This paper addresses the problem of efficiently restoring sufficient resources in a communications network to support the demand of mission critical services after a large scale disruption. We give a formulation of the problem as an MILP and show that it is NP-hard. We propose a polynomial time heuristic, called Iterative Split and Prune (ISP) that decomposes the original problem recursively into smaller problems, until it determines the set of network components to be restored. We performed extensive simulations by varying the topologies, the demand intensity, the number of critical services, and the disruption model. Compared to several greedy approaches ISP performs better in terms of number of repaired components, and does not result in any demand loss. It performs very close to the optimal when the demand is low with respect to the supply network capacities, thanks to the ability of the algorithm to maximize sharing of repaired resources
    • …
    corecore