Model-Independent Determinations of B -> D l nu , D* l nu Form Factors

We present nonperturbative, model-independent parametrizations of the individual QCD form factors relevant to B -> D* l nu and B -> D l nu decays. These results follow from dispersion relations and analyticity, without recourse to heavy quark symmetry. To describe a form factor with two percent accuracy, three parameters are necessary, one of which is its normalization at zero recoil, F(1). We combine the individual form factors using heavy quark symmetry to extract values for the product |V_{cb}| F(1) from B -> D* l nu data with negligible extrapolation uncertainty.Comment: uses harvmac and epsf, 22 pages, 3 eps figures include

Cover Pebbling Hypercubes

Given a graph G and a configuration C of pebbles on the vertices of G, a pebbling step removes two pebbles from one vertex and places one pebble on an adjacent vertex. The cover pebbling number g=g(G) is the minimum number so that every configuration of g pebbles has the property that, after some sequence of pebbling steps, every vertex has a pebble on it. We prove that the cover pebbling number of the d-dimensional hypercube Q^d equals 3^d.Comment: 11 page

Optimal Pebbling in Products of Graphs

We prove a generalization of Graham's Conjecture for optimal pebbling with arbitrary sets of target distributions. We provide bounds on optimal pebbling numbers of products of complete graphs and explicitly find optimal $t$-pebbling numbers for specific such products. We obtain bounds on optimal pebbling numbers of powers of the cycle $C_5$. Finally, we present explicit distributions which provide asymptotic bounds on optimal pebbling numbers of hypercubes.Comment: 28 pages, 1 figur

Nativism, civic nationalism and the malleability of voter attitudes

Nativism is one of the defining phenomena of the contemporary era. Yet, we know little about how malleable citizen attitudes associated with nativism and nationalism are to priming effects when media frames which deal with key issues such as immigration are introduced. In this article, we present the findings from a survey experiment fielded to a nationally representative sample of voters in Australia in May 2019. In it, we explore whether the attitudes of voters for different political parties can be primed by introducing two contrasting media frames to measure these effects. We find positive and negative frames have no effect on the attitudes of voters for Australia’s populist radical right party, but that the former has an effect on centre-right voters in Australia. Such findings have important implications for our understanding of political communication and the malleability of political attitudes

The Unusual Temporal and Spatial Slip History of the Wassuk Range Normal Fault, Western Nevada (USA): Implications for Seismic Hazard and Walker Lane Deformation

We document temporal and spatial variations in vertical displacement rate across 6 temporal orders of magnitude to better under stand how the 100-km-long, east-dipping Wassuk Range normal fault system has accommodated strain in the context of the Walker Lane, a tectonically active, NNWtrending zone of dextral and extensional deformation that affects significant portions of western Nevada and eastern California. We combine 10Be and 26Al cosmonuclide exposure ages with shallow seismic and gravity data from the buried hanging wall of the Wassuk fault to derive a post-113 ka (105 yr time scale) vertical displacement rate of 0.82 ± 0.16 mm/yr. We also perform largescale fault scarp analysis to constrain the long-term (\u3e1 Ma; 106 yr time scale) displacement rate. Our fault-scarp analysis results imply similar vertical displacement rates, with higher long-term vertical displacement rates along the southern fault (-1.1 mm/yr) relative to the northern fault (6, 105, 103, and 101 yr time scales (this study and others) support a constant vertical displacement rate between 0.75 and 1.0 mm/yr for the Wassuk Range fault since ca. 4 Ma. An anomalously high vertical displacement rate at the 104 yr time scale is best explained by an earthquake cluster between ca. 15.5 ka and ca. 10.5 ka, potentially linked to rapid filling of the Walker Lake basin immediately prior to the ca. 13 ka Sehoo highstand of ancestral Lake Lahontan. We hypothesize that this flood event induced seismicity by placing an additional load on the hanging wall of the Wassuk Range fault and by increasing the pore-fluid pressure within and adjacent to the fault. Although an earthquake cluster like this is consistent with Wallace-type fault behavior, we suggest that a nontectonic stressor induced the cluster, resulting in the apparent discrepancy in vertical displacement rate at the 104 yr time scale. Thus, we posit that the long-term slip along Wassuk fault is better explained by slip-predictable Reid-type behavior, which deviates from the behavior of other well-documented fault systems. Based on these results, we suggest that similar, unrecognized nontectonic stressors may influence rates of strain release along other major fault systems worldwide. Finally, we present a revised model of central Walker Lane kinematics, based on data from this and other recent studies