829 research outputs found
Explicit congruences for mock modular forms
No full textIn recent work of Bringmann, Guerzhoy, and the first author, -adic modular forms were constructed from mock modular forms. We look at a specific case, starting with a weight -10 mock modular form, and prove explicit congruences.postprin
The clustering of galaxies in the SDSS-III DR9 Baryon Oscillation Spectroscopic Survey: constraints on primordial non-Gaussianity
No full text12 pages, 7 figuresWe analyze the density field of 264,283 galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) and included in the SDSS data release nine (DR9). In total, the SDSS DR9 BOSS data includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of more than 3,000 deg^2. We measure the power spectrum of these galaxies with redshifts 0.43 0), is 99.5%. After quantifying and correcting for the systematic bias and including the added uncertainty, we find -92 0) = 91.0%. A more conservative approach assumes that we have only learned the k-dependence of the systematic bias and allows any amplitude for the systematic correction; we find that the systematic effect is not fully degenerate with that of f_NL,local, and we determine that -168 0) = 68%. This analysis demonstrates the importance of accounting for the impact of Galactic foregrounds on f_NL,local measurements. We outline the methods that account for these systematic biases and uncertainties. We expect our methods to yield robust constraints on f_NL,local for both our own and future large-scale-structure investigations
On Jacobi–Weierstrass mock modular forms
No full textAlfes C, Funke J, Mertens M, Rosu E. On Jacobi–Weierstrass mock modular forms. Advances in Mathematics. 2023;465: 110147.We construct harmonic weak Maass forms that map to cusp forms of weight
with rational coefficients under the -operator. This generalizes
work of the first author, Griffin, Ono, and Rolen, who constructed
distinguished preimages under this differential operator of weight newforms
associated to rational elliptic curves using the classical Weierstrass theory
of elliptic functions. We extend this theory and construct a vector-valued
Jacobi--Weierstrass -function which is a generalization of the classical
Weierstrass -function
An investigation into stent expansion using numerical and experimental techniques
No full textExtensive finite element analyses have been carried out by researchers to investigate the difference in the mechanical loading induced in vessels stented with various different stent designs and the influence of this loading on restenosis outcome. This study investigates the experimental validation of these numerical stent expansions using compliant mock arteries. The development of this in-vitro validation test has the prospect of providing a fully validated preclinical testing tool which can be used to optimise stent designs.
Mock arteries were developed as straight cylindrical vessels using a specially designed rig such that they had an inner lumen diameter of 3 mm and a thickness of 0.5 mm, thus representing a typical porcine coronary artery geometry. These mock arteries were manufactured from compliant Sylgard elastomer 184 (Dow Corning). This material was chosen mainly due to its inherent variable elastic properties which are determined by its curing process and ratio of elastomer to curing agent. Extensive testing was carried out on samples of porcine coronary arteries and differing ratios of Sylgard to identify a close match in mechanical properties to those of porcine coronary arteries. Driver stents (Medtronic AVE) were expanded both freely and inside these mock arteries and the subsequent deformation recorded using a video extensometer.
The Driver stent was numerically modelled with a strut thickness of 0.09 mm and an overall length of 9 mm such that each modular element had a length of 1 mm. The material for the stent was described using an elasto-plastic material model whereby the linear elasticity was defined using values for MP35N cobalt chromium alloy: Young's Modulus of 232 GPa, Poisson's Ratio of 0.26. A piecewise linear function was used to represent the non-linear plasticity of the material through a von Mises plasticity model with isotropic hardening. Due to symmetry, only one-quarter of the geometry was modelled in the circumferential direction. The mock artery was represented as a hyperelastic material, the constitutive equation determined by fitting to the uniaxial tension tests of Sylgard elastomeric material. A uniform pressure was applied to the internal surface of each stent to represent a balloon expansion.
This study identified a suitable material for use as a blood vessel substitute such that experimental stent expansions could be carried out within the mock artery and the results used to evaluate the accuracy of the numerical methods. Finite element analyses were carried out to examine two separate methods for stent expansion such that the most accurate and effective method could be determined. Results show that the numerical methods used in simulating the free expansion, and expansion inside a mock artery of the Driver stent, can accurately describe the in-vitro stent expansion. Both experimental and numerical models were found to achieve similar amounts of foreshortening, longitudinal recoil and radial recoil
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A Mock Catalog of Gravitationally-lensed Quasars for the LSST Survey
No full textWe present a mock catalog of gravitationally-lensed quasars at z qso 0.″07 and quasar absolute magnitude M i 0.″5, which will at least be marginally resolved in LSST images with seeing of ∼0.″7. There will be ∼200 quadruply-lensed quasars discoverable in the LSST. The fraction of quad lenses among all discoverable lensed quasars is about ∼10%-15%, and this fraction decreases with survey depth. This mock catalog shows a large diversity in the observational features of lensed quasars, in terms of lensing separation and quasar-to-deflector flux ratio. We discuss possible strategies for a complete search of lensed quasars in the LSST era. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
A review of the scholarship on Ebenezer Cook and a critical assessment of his works
No full textInterest in Ebenezer Cook has increased steadily, if slowly, since Moses Coit Tyler wrote an enthusiastic critique of The Sot-weed Factor in A History of American Literature, 1607-1765 in 1878. Much of that interest, however, has been little more than curiosity about a minor poet who remains an elusive literary figure of early eighteenth-century Maryland; even today, in spite of several recent assessments of his major poem s, relatively little critical attention has been given to the works of this often robust and witty author who wrote what are apparently the first American Hudibrastic poem, the first American mock-heroic, and the first belletristic work composed and published in the colonies south of Pennsylvania. Neither has there ever been a complete edition of the Cook canon, which consists, as far as we know, of three major poems--The Sotweed Factor (1708, revised extensively in 1731), Sotweed Redivivus (1730), and The History of Colonel Nathaniel Bacon's Rebellion in Virginia (1731)--and four elegies addressed to prominent Maryland citizens of Cook's day. This dissertation provides a comprehensive study of Ebenezer Cook that include critical analyses of all his known poems and transcriptions of the current canon based on first editions or earliest-known copies and manuscripts as w ell as historical background and commentary (much of Cook's poetry contains observations on the political, social, and economic issues of contemporary Maryland), bibliographical data, and a survey of Cook scholarship
Cosmological constraints from the clustering of the Sloan Digital Sky Survey DR7 luminous red galaxies
No full textWe present the power spectrum of the reconstructed halo density field derived from a sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7). The halo power spectrum has a direct connection to the underlying dark matter power for k ≤ 0.2 h Mpc −1 , well into the quasi-linear regime. This enables us to use a factor of ∼8 more modes in the cosmological analysis than an analysis with k max = 0.1 h Mpc −1 , as was adopted in the SDSS team analysis of the DR4 LRG sample. The observed halo power spectrum for 0.02 < k < 0.2 h Mpc −1 is well fitted by our model: χ 2 = 39.6 for 40 degrees of freedom for the best-fitting Λ cold dark matter (ΛCDM) model. We find Ω m h 2 ( n s /0.96) 1.2 = 0.141 +0.010 −0.012 for a power-law primordial power spectrum with spectral index n s and Ω b h 2 = 0.022 65 fixed, consistent with cosmic microwave background measurements. The halo power spectrum also constrains the ratio of the comoving sound horizon at the baryon-drag epoch to an effective distance to z = 0.35: r s / D V (0.35) = 0.1097 +0.0039 −0.0042 . Combining the halo power spectrum measurement with the Wilkinson Microwave Anisotropy Probe ( WMAP ) 5 year results, for the flat ΛCDM model we find Ω m = 0.289 ± 0.019 and H 0 = 69.4 ± 1.6 km s −1 Mpc −1 . Allowing for massive neutrinos in ΛCDM, we find eV at the 95 per cent confidence level. If we instead consider the effective number of relativistic species N eff as a free parameter, we find N eff = 4.8 +1.8 −1.7 . Combining also with the Kowalski et al. supernova sample, we find Ω tot = 1.011 ± 0.009 and w =−0.99 ± 0.11 for an open cosmology with constant dark energy equation of state w . The power spectrum and a module to calculate the likelihoods are publicly available at http://lambda.gsfc.nasa.gov/toolbox/lrgdr/ .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79328/1/j.1365-2966.2010.16276.x.pd
Anchoring effects in the development of false childhood memories
No full textWhen people receive descriptions or doctored photos of events that never happened, they often come to remember those events. But if people receive both a description and a doctored photo, does the order in which they receive the information matter? We asked people to consider a description and a doctored photograph of a childhood hot air balloon ride, and we varied which medium they saw first. People who saw a description first reported more false images and memories than people who saw a photo first, a result that fits with an anchoring account of false childhood memories
Pianola Karaoke and other attractions: resisting the homogenisation of cultural memory embedded in material sites
No full textNo abstract available
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