398,942 research outputs found

    Coupled oscillators and Feynman's three papers

    Get PDF
    According to Richard Feynman, the adventure of our science of physics is a perpetual attempt to recognize that the different aspects of nature are really different aspects of the same thing. It is therefore interesting to combine some, if not all, of Feynman's papers into one. The first of his three papers is on the ``rest of the universe'' contained in his 1972 book on statistical mechanics. The second idea is Feynman's parton picture which he presented in 1969 at the Stony Brook conference on high-energy physics. The third idea is contained in the 1971 paper he published with his students, where they show that the hadronic spectra on Regge trajectories are manifestations of harmonic-oscillator degeneracies. In this report, we formulate these three ideas using the mathematics of two coupled oscillators. It is shown that the idea of entanglement is contained in his rest of the universe, and can be extended to a space-time entanglement. It is shown also that his parton model and the static quark model can be combined into one Lorentz-covariant entity. Furthermore, Einstein's special relativity, based on the Lorentz group, can also be formulated within the mathematical framework of two coupled oscillators.Comment: 31 pages, 6 figures, based on the concluding talk at the 3rd Feynman Festival (Collage Park, Maryland, U.S.A., August 2006), minor correction

    Competitively tight graphs

    Full text link
    The competition graph of a digraph DD is a (simple undirected) graph which has the same vertex set as DD and has an edge between two distinct vertices xx and yy if and only if there exists a vertex vv in DD such that (x,v)(x,v) and (y,v)(y,v) are arcs of DD. For any graph GG, GG together with sufficiently many isolated vertices is the competition graph of some acyclic digraph. The competition number k(G)k(G) of a graph GG is the smallest number of such isolated vertices. Computing the competition number of a graph is an NP-hard problem in general and has been one of the important research problems in the study of competition graphs. Opsut [1982] showed that the competition number of a graph GG is related to the edge clique cover number θE(G)\theta_E(G) of the graph GG via θE(G)−∣V(G)∣+2≤k(G)≤θE(G)\theta_E(G)-|V(G)|+2 \leq k(G) \leq \theta_E(G). We first show that for any positive integer mm satisfying 2≤m≤∣V(G)∣2 \leq m \leq |V(G)|, there exists a graph GG with k(G)=θE(G)−∣V(G)∣+mk(G)=\theta_E(G)-|V(G)|+m and characterize a graph GG satisfying k(G)=θE(G)k(G)=\theta_E(G). We then focus on what we call \emph{competitively tight graphs} GG which satisfy the lower bound, i.e., k(G)=θE(G)−∣V(G)∣+2k(G)=\theta_E(G)-|V(G)|+2. We completely characterize the competitively tight graphs having at most two triangles. In addition, we provide a new upper bound for the competition number of a graph from which we derive a sufficient condition and a necessary condition for a graph to be competitively tight.Comment: 10 pages, 2 figure

    Lens optics as an optical computer for group contractions

    Get PDF
    It is shown that the one-lens system in para-axial optics can serve as an optical computer for contraction of Wigner's little groups and an analogue computer which transforms analytically computations on a spherical surface to those on a hyperbolic surface. It is shown possible to construct a set of Lorentz transformations which leads to a two-by-two matrix whose expression is the same as those in the para-axial lens optics. It is shown that the lens focal condition corresponds to the contraction of the O(3)-like little group for a massive particle to the E(2)-like little group for a massless particle, and also to the contraction of the O(2,1)-like little group for a space-like particle to the same E(2)-like little group. The lens-focusing transformations presented in this paper allow us to continue analytically the spherical O(3) world to the hyperbolic O(2,1) world, and vice versa.Comment: 14 pages, RevTeX, no figure

    Norm Estimates for the Difference Between Bochner's Integral and the Convex Combination of Function's Values

    Full text link
    Norm estimates are developed between the Bochner integral of a vector-valued function in Banach spaces having the Radon-Nikodym property and the convex combination of function values taken on a division of the interval [a,b]

    A note on the values of the weighted q-Bernstein polynomials and modified q-Genocchi numbers with weight alpha and beta via the p-adic q-integral on Zp

    Get PDF
    The rapid development of q-calculus has led to the discovery of new generalizations of Bernstein polynomials and Genocchi polynomials involving q-integers. The present paper deals with weighted q-Bernstein polynomials and q-Genocchi numbers with weight alpha and beta. We apply the method of generating function and p-adic q-integral representation on Zp, which are exploited to derive further classes of Bernstein polynomials and q-Genocchi numbers and polynomials. To be more precise we summarize our results as follows, we obtain some combinatorial relations between q-Genocchi numbers and polynomials with weight alpha and beta. Furthermore, we derive an integral representation of weighted q-Bernstein polynomials of degree n on Zp. Also we deduce a fermionic p-adic q-integral representation of product weighted q-Bernstein polynomials of different degrees n1,n2,...on Zp and show that it can be written with q-Genocchi numbers with weight alpha and beta which yields a deeper insight into the effectiveness of this type of generalizations. Our new generating function possess a number of interesting properties which we state in this paper.Comment: 10 page
    • …
    corecore