Manifolds with parallel differential forms and Kaehler identities for G_2-manifolds

Let M be a compact Riemannian manifold equipped with a parallel differential form \omega. We prove a version of Kaehler identities in this setting. This is used to show that the de Rham algebra of M is weakly equivalent to its subquotient $(H^*_c(M), d)$, called {\bf the pseudocohomology} of M. When M is compact and Kaehler and \omega is its Kaehler form, $(H^*_c(M), d)$ is isomorphic to the cohomology algebra of M. This gives another proof of homotopy formality for Kaehler manifolds, originally shown by Deligne, Griffiths, Morgan and Sullivan. We compute $H^i_c(M)$ for a compact G_2-manifold, showing that it is isomorphic to cohomology unless i=3,4. For i=3,4, we compute $H^*_c(M)$ explicitly in terms of the first order differential operator *d: \Lambda^3(M)\arrow \Lambda^3(M).Comment: 34 pages, minor corrections, bibliography expande

Studien zur Altägyptischen Kultur Nr. 39 (2010) - Abstracts

Abstracts der Artikel zu "SAK" 39 (2010). Die Autoren sind: M. Abdelrahiem; Kh. H. Awad; H. Beinlich; A. Bettum; F. Breyer; G.P.F. Broekman; R. Bußmann; R. Gundacker; S. Herrmann; J.M. Iskander; J.E. Jay; J. Kahl/M. El-Khadragy/U. Verhoeven/S. Prell/I. Eichner/Th. Beckh; D. Klotz; B. Lurson; E.-E. Morgan; R. Nutz; M. Nuzzolo; D. Stefanovic; Ch. Theis; D. Topmann und S. Uljas

Studien zur Altägyptischen Kultur Nr. 34 (2006) - Abstracts

Abstracts der Artikel zu SAK 34 (2006). Die Autoren sind: M. Abdelrahiem, H. Beinlich, E. Bernhauer, N. Billing. S. Bojowald, A. Busch, M. Depauw, K. Dohrmann, M. von Falck, F. Förster, D. Franke, H. Goedicke, W. Grajetzki, K. Jansen-Winkeln, J. Kahl/M. el-Khadragy/U. Verhoeven with an appendix by U. Fauerbach, D. el Kahn, D. Klotz, C. Leitz, K. Lembke, E.-E. Morgan, R. Preys, J.F. Quack, U. Rumme

Preacher\u27s Magazine Volume 62 Number 03

THE MINISTER’S MONEY INSUFFICIENT FUNDS, D. Martin Butler WHEN THE CREDIT TRAP SNAPS, Kenneth Heer INVESTING ON A SMALL SALARY, Darold H. Morgan RETIREMENT SAVINGS: THE HIGH COST OF WAITING, Paul D. Fitzgerald REIMBURSEMENT: SIMPLIFY YOUR TAX RETURN AND SAVE, Don Walter PRINCIPLES FOR SAVING AND INVESTING, Bert Martin WHERE TO FIND FINANCIAL INFORMATION, William C. Miller “WHERE DID ALL THE MONEY GO?” Darold H. Morgan ATTITUDES TOWARD MONEY, Lee McCleery COULD IT HAPPEN AGAIN? Wayne E. Caldwell FEATURE ARTICLES John Wesley’s Covenant Service Tell Us Again, Mary, Fletcher L. Tink Pentecost Ignites Revival, Delbert R. Rose The Trinity and Contemporary Thought, David L. Smith Preventing Stress and Depression, Don Harvey The Day of Yahweh, Stephen Green The Fishing Hole, William W. Woods REGULAR FEATURES Suitable for Framing Editorial FINANCE: Can Ministers Opt Out of Social Security? Preacher’s Exchange Today’s Books for Today’s Preacher Sermon Outlines Sermon Illustrations We Get Letters Ark Rockerhttps://digitalcommons.olivet.edu/cotn_pm/1644/thumbnail.jp

Stable sheaves on elliptic fibrations

We characterize the subscheme of the moduli space of torsion-free sheaves on an elliptic surface which are stable of relative degree zeero (with respect to a polarization of type aH+bf, H being the section and f the elliptic fibre) which is isomorphic, via the relative Fourier-Mukai transform, with the relative compactified Simpson Jacobian of the family of those curves D in the surface which are flat over the base of the elliptic fibration. This generalizes and completes earlier constructions due to Friedman, Morgan and Witten. We also study the relative moduli scheme of sheaves whose restriction to each fibre is torsion-free and semistable of rank n and degree zero for higher dimensional elliptic fibrations. The relative Fourier-Mukai transform induces an isomorphic between this relative moduli space and the relative n-th symmetric product of the fibration.Comment: AMS-LaTeX, 18 pages, XY-pic; new title, some modifications; final version as accepted in J. Geom. Phy

Harpur Palate, Volume 9, Issue 2, Winter 2010

Contributors: Ruth Thompson | Vanessa Blakeslee | Darryl Crawford | Patrick Crerand | Jason DeYoung | Jaquira Díaz | Tim Hedges | Jennifer D. Munro | Kimberly Quiogue Andrews | Amy Ash | Cynthia Atkins | Kaveh Bassiri | F.J. Bergmann | Jaime Brunton | Adam Clay | Christina Cook | Phil Estes | Mary Beth Ferda | Rebecca Morgan Frank | Brandi George | Arthur Gottleib | Robert H. Guard | Michael Hall | Jenny Hanning | William A. Henkin | Michael Jenkins | Jill McCabe Johnson | Ellen LaFleche | R.J. Lambert | Cynthia Lowen | Travis Mossotti | Linda Lancione Moyet | Nikoletta Nousiopoulos | Jennifer Perrine | Romy Ruukel | Emily Scudder | Brooke Sheridan | Theresa D. Smith | Bonnie Stanard | Mark Wagenaar | Stephen Lloyd Webber | Jonathan Wells | Marcus Wicker | Lindsay Wilson | Paul Roger

An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology

We study the IR-through-UV interstellar extinction curves towards 328 Galactic B and late-O stars. We use a new technique which employs stellar atmosphere models in lieu of unreddened "standard" stars. This technique is capable of virtually eliminating spectral mismatch errors in the curves. It also allows a quantitative assessment of the errors and enables a rigorous testing of the significance of relationships between various curve parameters, regardless of whether their uncertainties are correlated. Analysis of the curves gives the following results: (1) In accord with our previous findings, the central position of the 2175 A extinction bump is mildly variable, its width is highly variable, and the two variations are unrelated. (2) Strong correlations are found among some extinction properties within the UV region, and within the IR region. (3) With the exception of a few curves with extreme (i.e., large) values of R(V), the UV and IR portions of Galactic extinction curves are not correlated with each other. (4) The large sightline-to-sightline variation seen in our sample implies that any average Galactic extinction curve will always reflect the biases of its parent sample. (5) The use of an average curve to deredden a spectral energy distribution (SED) will result in significant errors, and a realistic error budget for the dereddened SED must include the observed variance of Galactic curves. While the observed large sightline-to-sightline variations, and the lack of correlation among the various features of the curves, make it difficult to meaningfully characterize average extinction properties, they demonstrate that extinction curves respond sensitively to local conditions. Thus, each curve contains potentially unique information about the grains along its sightline.Comment: To appear in the Astrophysical Journal, Part 1, July 1, 2007. Figures and Tables which will appear only in the electronic version of the Journal can be obtained via anonymous ftp from ftp://ftp.astronomy.villanova.edu . After logging in, change directories to "fitz/FMV_EXTINCTION". A README file describes the various files present in the director

Thysanoptera (Thrips) Within Citrus Orchards in Florida: Species Distribution, Relative and Seasonal Abundance Within Trees, and Species on Vines and Ground Cover Plants

Seven citrus orchards on reduced to no pesticide spray programs were sampled for Thysanoptera in central and south central Florida. Inner and outer canopy leaves, fruits, twigs, trunk scrapings, vines and ground cover plants were sampled monthly between January 1995 and January 1996. Thirty-six species of thrips were identified from 2,979 specimens collected from within citrus tree canopies and 18,266 specimens from vines and ground cover plants within the seven citrus orchards. The thrips species included seven predators [Aleurodothrips fasciapennis (Franklin), Karnyothrips flavipes (Jones), K. melaleucus (Bagnall), Leptothrips cassiae (Watson), L. macroocellatus (Watson), L. pini (Watson), and Scolothrips sexmaculatus (Pergande)] 21 plant feeding species [Anaphothrips n. sp., Arorathrips mexicanus (Crawford), Aurantothrips orchidaceous (Bagnall), Baileyothrips limbatus (Hood), Chaetanaphothrips orchidii (Moulton), Danothrips trifasciatus (Sakimura), Echinothrips americanus (Morgan), Frankliniella bispinosa (Morgan), F. cephalica (Crawford), F. fusca (Hinds), F. gossypiana (Hood), Frankliniella sp. (runneri group), Haplothrips gowdeyi (Franklin), Heliothrips haemorrhoidalis (Bouché), Leucothrips piercei (Morgan), Microcephalothrips abdominalis (Crawford), Neohydatothrips floridanus (Watson), N. portoricensis (Morgan), Pseudothrips inequalis (Beach), Scirtothrips sp., and Thrips hawaiiensis (Morgan)]; and eight fungivorous feeding species [Adraneothrips decorus (Hood), Hoplandrothrips pergandei (Hinds), Idolothripinae sp., Merothrips floridensis (Watson), M. morgani (Hood), Neurothrips magnafemoralis (Hinds), Stephanothrips occidentalis Hood and Williams, and Symphyothrips sp.]. Only F. bispinosa, C. orchidii, D. trifasciatus, and H. haemorrhoidalis have been considered economic pests on Florida citrus. Scirtothrips sp. and T. hawaiiensis were recovered in low numbers within Florida citrus orchards. Both are potential pest species to citrus and possibly other crops in Florida. The five most abundant thrips species collected within citrus tree canopies were: A. fasciapennis, F. bispinosa, C. orchidii, K. flavipes, and D. trifasciatus. In comparison, the following five thrips species were most abundant on vines or ground cover plants: F. bispinosa, H. gowdeyi, F. cephalica, M. abdominalis, and F. gossypiana. Fifty-eight species of vines or ground cover plants in 26 families were infested with one or more of 27 species of thrips

A Search for Wolf-Rayet Stars in the Small Magellanic Cloud

We conducted an extensive search for Wolf-Rayet stars (W-Rs) in the SMC, using the same interference filter imaging techniques that have proved successful in finding W-Rs in more distant members of the Local Group. Photometry of some 1.6 million stellar images resulted in some 20 good candidates, which we then examined spectroscopically. Two of these indeed proved to be newly found W-Rs, bringing the total known in the SMC from 9 to 11. Other finds included previously unknown Of-type stars (one as early as O5f?p)),the recovery of the Luminous Blue Variable S18, and the discovery of a previously unknown SMC symbiotic star. More important, however, is the fact that there does not exist a significant number of W-Rs waiting to be discovered in the SMC. The number of W-Rs in the SMC is a factor of 3 lower than in the LMC (per unit luminosity), and we argue this is the result of the SMC's low metallicity on the evolution of the most massive stars.Comment: Accepted by Astrophysical Journal. Postscript version available via ftp.lowell.edu/pub/massey/smcwr.ps.gz Revised version contains slightly revised spectral types for the Of stars but is otherwise unchange

Supersoft X-ray Sources in M31: I. A Chandra Survey and an Extension to Quasisoft Sources

We report on very soft X-ray sources (VSSs) in M31. In a survey which was most sensitive to soft sources in four 8'x8' regions covered by Chandra's ACIS-S S3 CCD, we find 33 VSSs that appear to belong to M31. Fifteen VSSs have spectral characteristics mirroring the supersoft X-ray sources studied in the Magellanic Cloud and Milky Way ($k T_{eff} \leq 100$ eV); we therefore call these ``classical'' supersoft sources, or simply supersoft sources (SSSs). Eighteen VSSs may either have small (< 10%) hard components, or slightly higher effective temperatures (but still < 350 eV). We refer to these VSSs as quasisoft sources (QSSs). While hot white dwarf models may apply to SSSs, the effective temperatures of QSSs are too high, unless, e.g., the radiation emanates from only a small portion of surface. Two of the SSSs were first detected and identified as such through ROSAT observations. One SSS and one QSS may be identified with symbiotics, and 2 SSSs with supernova remnants. Both SSSs and QSSs in the disk are found near star-forming regions, possibly indicating that they are young. VSSs in the outer disk and halo are likely to be old systems; in these regions, there are more QSSs than SSSs, which is opposite to what is found in fields closer to the galaxy center. The largest density of bright VSSs is in the bulge; some of the bulge sources are close enough to the nucleus to be remnants of the tidal disruption of a giant by the massive central black hole. By using Chandra data in combination with ROSAT and XMM observations, we find most VSSs to be highly variable, fading from or brightening toward detectability on time scales of months. There is evidence for VSSs with low luminosities ($\sim 10^{36}$ erg s$^{-1}$).Comment: 14 pages, 4 figures. Accepted for publication in ApJ. Classification of supersoft and quasisoft sources is clarifie