254,014 research outputs found

    Lattices with non-Shannon Inequalities

    Full text link
    We study the existence or absence of non-Shannon inequalities for variables that are related by functional dependencies. Although the power-set on four variables is the smallest Boolean lattice with non-Shannon inequalities there exist lattices with many more variables without non-Shannon inequalities. We search for conditions that ensures that no non-Shannon inequalities exist. It is demonstrated that 3-dimensional distributive lattices cannot have non-Shannon inequalities and planar modular lattices cannot have non-Shannon inequalities. The existence of non-Shannon inequalities is related to the question of whether a lattice is isomorphic to a lattice of subgroups of a group.Comment: Ten pages. Submitted to ISIT 2015. The appendix will not appear in the proceeding

    Social Exchange and the Maintenance of Order in Status-Stratified Systems

    Get PDF
    This paper examines the role of social exchange in the construction of microorder within status-differentiated relations. How order is constructed and maintained in the context of social inequality is a classic sociological problem. We use a serendipitous finding from a recent experiment as a stimulus for theorizing an important feature of this larger problem of order. The finding is that, in an experiment where African-American females negotiated with white males, the white males received much larger payoffs than the African-American females. Yet, despite substantial power and profit differentiation advantaging white males, both individuals reported positive feelings (pleasure/satisfaction and interest/excitement) to the same degree, which contradicts most research on emotional responses to power. We argue that these similar emotional responses, in the context of substantial payoff inequalities, are due to parallel, joint effects of (a) status processes that create and legitimate initial profit differences and (b) exchange processes that make salient a relationship between the actors during repeated exchange. This explanation integrates notions of status value, referential structure, and legitimacy from status theories with notions of relational cohesion and shared responsibility from exchange theories. Broadly, the paper proposes some ways to productively interweave ideas from status and exchange theories to explain the emergence or maintenance of enduring social inequalities

    Information inequalities and Generalized Graph Entropies

    Get PDF
    In this article, we discuss the problem of establishing relations between information measures assessed for network structures. Two types of entropy based measures namely, the Shannon entropy and its generalization, the R\'{e}nyi entropy have been considered for this study. Our main results involve establishing formal relationship, in the form of implicit inequalities, between these two kinds of measures when defined for graphs. Further, we also state and prove inequalities connecting the classical partition-based graph entropies and the functional-based entropy measures. In addition, several explicit inequalities are derived for special classes of graphs.Comment: A preliminary version. To be submitted to a journa

    Bell's inequalities in the tomographic representation

    Get PDF
    The tomographic approach to quantum mechanics is revisited as a direct tool to investigate violation of Bell-like inequalities. Since quantum tomograms are well defined probability distributions, the tomographic approach is emphasized to be the most natural one to compare the predictions of classical and quantum theory. Examples of inequalities for two qubits an two qutrits are considered in the tomographic probability representation of spin states.Comment: 11 pages, comments and references adde

    Positivity, entanglement entropy, and minimal surfaces

    Full text link
    The path integral representation for the Renyi entanglement entropies of integer index n implies these information measures define operator correlation functions in QFT. We analyze whether the limit n→1n\rightarrow 1, corresponding to the entanglement entropy, can also be represented in terms of a path integral with insertions on the region's boundary, at first order in n−1n-1. This conjecture has been used in the literature in several occasions, and specially in an attempt to prove the Ryu-Takayanagi holographic entanglement entropy formula. We show it leads to conditional positivity of the entropy correlation matrices, which is equivalent to an infinite series of polynomial inequalities for the entropies in QFT or the areas of minimal surfaces representing the entanglement entropy in the AdS-CFT context. We check these inequalities in several examples. No counterexample is found in the few known exact results for the entanglement entropy in QFT. The inequalities are also remarkable satisfied for several classes of minimal surfaces but we find counterexamples corresponding to more complicated geometries. We develop some analytic tools to test the inequalities, and as a byproduct, we show that positivity for the correlation functions is a local property when supplemented with analyticity. We also review general aspects of positivity for large N theories and Wilson loops in AdS-CFT.Comment: 36 pages, 10 figures. Changes in presentation and discussion of Wilson loops. Conclusions regarding entanglement entropy unchange

    Correlation functions, Bell's inequalities and the fundamental conservation laws

    Full text link
    I derive the correlation function for a general theory of two-valued spin variables that satisfy the fundamental conservation law of angular momentum. The unique theory-independent correlation function is identical to the quantum mechanical correlation function. I prove that any theory of correlations of such discrete variables satisfying the fundamental conservation law of angular momentum violates the Bell's inequalities. Taken together with the Bell's theorem, this result has far reaching implications. No theory satisfying Einstein locality, reality in the EPR-Bell sense, and the validity of the conservation law can be constructed. Therefore, all local hidden variable theories are incompatible with fundamental symmetries and conservation laws. Bell's inequalities can be obeyed only by violating a conservation law. The implications for experiments on Bell's inequalities are obvious. The result provides new insight regarding entanglement, and its measures.Comment: LaTeX, 12pt, 11 pages, 2 figure
    • …
    corecore