Dynamics of Uniform Quantum Gases, I: Density and Current Correlations

A unified approach valid for any wavenumber, frequency, and temperature is presented for uniform ideal quantum gases allowing for a comprehensive study of number density and particle-current density response functions. Exact analytical expressions are obtained for spectral functions in terms of polylogarithms. Also, particle-number and particle-current static susceptibilities are presented which, for fugacity less than unity, additionally involve Kummer functions. The wavenumber and temperature dependent transverse-current static susceptibility is used to show explicitly that current correlations are of a long range in a Bose-condensed uniform ideal gas but for bosons above the critical temperature and for Fermi and Boltzmann gases at all temperatures these correlations are of short range. Contact repulsive interactions for systems of neutral quantum particles are considered within the random-phase approximation. The expressions for particle-number and transverse-current susceptibilities are utilized to discuss the existence or nonexistence of superfluidity in the systems under consideration

Keyframe-based visual–inertial odometry using nonlinear optimization

Combining visual and inertial measurements has become popular in mobile robotics, since the two sensing modalities offer complementary characteristics that make them the ideal choice for accurate visual–inertial odometry or simultaneous localization and mapping (SLAM). While historically the problem has been addressed with filtering, advancements in visual estimation suggest that nonlinear optimization offers superior accuracy, while still tractable in complexity thanks to the sparsity of the underlying problem. Taking inspiration from these findings, we formulate a rigorously probabilistic cost function that combines reprojection errors of landmarks and inertial terms. The problem is kept tractable and thus ensuring real-time operation by limiting the optimization to a bounded window of keyframes through marginalization. Keyframes may be spaced in time by arbitrary intervals, while still related by linearized inertial terms. We present evaluation results on complementary datasets recorded with our custom-built stereo visual–inertial hardware that accurately synchronizes accelerometer and gyroscope measurements with imagery. A comparison of both a stereo and monocular version of our algorithm with and without online extrinsics estimation is shown with respect to ground truth. Furthermore, we compare the performance to an implementation of a state-of-the-art stochastic cloning sliding-window filter. This competitive reference implementation performs tightly coupled filtering-based visual–inertial odometry. While our approach declaredly demands more computation, we show its superior performance in terms of accuracy

Analytical pair correlations in ideal quantum gases: Temperature-dependent bunching and antibunching

The fluctuation-dissipation theorem together with the exact density response spectrum for ideal quantum gases has been utilized to yield a new expression for the static structure factor, which we use to derive exact analytical expressions for the temperature{dependent pair distribution function g(r) of the ideal gases. The plots of bosonic and fermionic g(r) display "Bose pile" and "Fermi hole" typically akin to bunching and antibunching as observed experimentally for ultracold atomic gases. The behavior of spin-scaled pair correlation for fermions is almost featureless but bosons show a rich structure including long-range correlations near T_c. The coherent state at T=0 shows no correlation at all, just like single-mode lasers. The depicted decreasing trend in correlation with decrease in temperature for T < T_c should be observable in accurate experiments.Comment: 8 pages, 1 figure, minor revisio

Stakeholders, Entrepreneurial Rent and Bounded Self-Interest

This paper examines how the change from an assumption of pure self-interest to an assumption of bounded self-interest alters basic propositions regarding the way entrepreneurs select, negotiate with and manage relationships with their initial set of stakeholders. Although a purely economic approach would focus on material cost as the sole consideration when conducting these activities, we argue that non-material factors such as reciprocity and fairness are potent forces during the initial resource acquisition process. We explain that non-material considerations are accounted for in negotiations with stakeholders and positive reciprocity is encouraged through openly sharing information with stakeholders about the value of their contributions to the venture. Furthermore, we expect that entrepreneurs do and should seek stakeholders with expectations about future outcomes that are complementary to their own. This analysis provides a new perspective on the creation of entrepreneurial rent that promises to provide an enhanced understanding of the resource acquisition process as well as guidance to practitioners and researchers

Summary -- Entrepreneurial Uncertainty: What Do Stakeholders Look For?

This paper proposes that in the early stages of a venture entrepreneurs can reduce uncertainty for stakeholders -- and raise the probability of attracting desirable stakeholders -- by exhibiting behaviors associated with fairness and justice. Actors base their reciprocal behaviors -- both positive and negative -- on their subjective perceptions of distributive, procedural and interactional justice. Thus, entrepreneurs can influence perceptions of fairness in early interactions with stakeholders. This paper extends the logic of reciprocity and fairness to the setting in which entrepreneurial firms are seeking to attract desirable stakeholders in order to commercialize innovations

How Much is Too Much? The Limits to Generous Treatment of Stakeholders

Firms must allocate some minimum amount of value to stakeholders in order to retain access to the resources they provide. Stakeholder theory suggests managers optimize firm-level performance by allocating more than this minimum amount. However, how much is too much? This article addresses the misleading notion that more is always better when it comes to the treatment of stakeholders and, in doing so, provides needed refinement of the boundary of stakeholder theory\u27s predictions. The upside for managers is guidance in distinguishing between the types of value-allocating behaviors that will lead to greater value creation in their firms and actions that are likely to reduce value overall

Approximate well-supported Nash equilibria in symmetric bimatrix games

The $\varepsilon$-well-supported Nash equilibrium is a strong notion of approximation of a Nash equilibrium, where no player has an incentive greater than $\varepsilon$ to deviate from any of the pure strategies that she uses in her mixed strategy. The smallest constant $\varepsilon$ currently known for which there is a polynomial-time algorithm that computes an $\varepsilon$-well-supported Nash equilibrium in bimatrix games is slightly below $2/3$. In this paper we study this problem for symmetric bimatrix games and we provide a polynomial-time algorithm that gives a $(1/2+\delta)$-well-supported Nash equilibrium, for an arbitrarily small positive constant $\delta$

Density Fluctuations in Uniform Quantum Gases

Analytical expressions are given for the static structure factor S(k) and the pair correlation function g(r) for uniform ideal Bose-Einstein and Fermi-Dirac gases for all temperatures. In the vicinity of Bose Einstein condensation (BEC) temperature, g(r) becomes long ranged and remains so in the condensed phase. In the dilute gas limit, g(r) of bosons & fermions do not coincide with Maxwell-Boltzmann gas but exhibit bunching & anti-bunching effect respectively. The width of these functions depends on the temperature and is scaled as \surd (inverse atomic mass). Our numerical results provide the precise quantitative values of suppression/increase (antibunching and bunching) of the density fluctuations at small distances in ideal quantum gases in qualitative agreement with the experimental observation for almost non-trapped dilute gases.Comment: 4 pages,8 figures,conferenc

Managing for Stakeholders, Stakeholder Utility Functions, and Competitive Advantage

This paper integrates some of the central concepts of stakeholder theory with the literatures on organizational justice and trust to explain firm competitiveness. It provides a detailed explanation of factors that facilitate acquisition of knowledge about stakeholder utility functions. In addition, it offers a knowledge-based analysis of how firms that manage for stakeholders can enjoy sustainable competitive benefits. These explanations provide a strong rationale for including stakeholder theory in the discussion of firm competitiveness and performance