2,812 research outputs found

    Primary cosmic radiation Status report for period ending Aug. 1968

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    High altitude balloon flights for detecting primary cosmic ray

    Astronomy at sub-millimeter wavelengths

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    The first flight test of a gondola containing a Newtonian telescope with a 16 in. primary mirror is described. Bolometer tests were conducted along with gondola design studies, and changes were made in the mechanical system as a result. Parts of the system were rebuilt and tested, and it was found that the flight system had redundant data recording capabilities. In the total flight record, about 160 large signals were noted; about half of these appeared to have the correct shape for genuine signals, and the other were clearly noise spikes (they were large but the signal shape could not have been produced by the observation of a celestial object)

    On the cohomological spectrum and support varieties for infinitesimal unipotent supergroup schemes

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    We show that if GG is an infinitesimal elementary supergroup scheme of height r\leq r, then the cohomological spectrum G|G| of GG is naturally homeomorphic to the variety Nr(G)\mathcal{N}_r(G) of supergroup homomorphisms ρ:MrG\rho: \mathbb{M}_r \rightarrow G from a certain (non-algebraic) affine supergroup scheme Mr\mathbb{M}_r into GG. In the case r=1r=1, we further identify the cohomological support variety of a finite-dimensional GG-supermodule MM as a subset of N1(G)\mathcal{N}_1(G). We then discuss how our methods, when combined with recently-announced results by Benson, Iyengar, Krause, and Pevtsova, can be applied to extend the homeomorphism Nr(G)G\mathcal{N}_r(G) \cong |G| to arbitrary infinitesimal unipotent supergroup schemes.Comment: Fixed some algebra misidentifications, primarily in Sections 1.3 and 3.3. Simplified the proof of Proposition 3.3.

    Academic Freedom and Its Defenders

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    Pioneer Mars 1979 mission options

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    A preliminary investigation of lower cost Mars missions which perform useful exploration objectives after the Viking/75 mission was conducted. As a study guideline, it was assumed that significant cost savings would be realized by utilizing Pioneer hardware currently being developed for a pair of 1978 Venus missions. This in turn led to the additional constraint of a 1979 launch with the Atlas/Centaur launch vehicle which has been designated for the Pioneer Venus missions. Two concepts, using an orbiter bus platform, were identified which have both good science potential and mission simplicity indicative of lower cost. These are: (1) an aeronomy/geology orbiter, and (2) a remote sensing orbiter with a number of deployable surface penetrometers

    Sky survey at far infrared wavelengths using a balloon-borne telescope

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    Localized sources of far infrared radiation (approximately 50 microns) have been detected during a high altitude balloon flight with a 40 cm telescope and silicon detectors. The flight system is described and preliminary results are presented. A large area of the sky has been scanned for localized sources of far infrared radiation, using a balloon-borne system that was sensitive to wavelengths beyond about 55 microns. Two Molectron silicon bolometers were used, with a Newtonian telescope having a 40 cm primary. The telescope was driven in azimuth at a fixed elevation; this mode of scanning was carried out for the duration of each of two balloon flights. The flight system is described

    Multipole structure of current vectors in curved spacetime

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    A method is presented which allows the exact construction of conserved (i.e. divergence-free) current vectors from appropriate sets of multipole moments. Physically, such objects may be taken to represent the flux of particles or electric charge inside some classical extended body. Several applications are discussed. In particular, it is shown how to easily write down the class of all smooth and spatially-bounded currents with a given total charge. This implicitly provides restrictions on the moments arising from the smoothness of physically reasonable vector fields. We also show that requiring all of the moments to be constant in an appropriate sense is often impossible; likely limiting the applicability of the Ehlers-Rudolph-Dixon notion of quasirigid motion. A simple condition is also derived that allows currents to exist in two different spacetimes with identical sets of multipole moments (in a natural sense).Comment: 13 pages, minor changes, accepted to J. Math. Phy

    Introduction

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    The implications of gamma-ray lines observed from the Orion complex

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    The observation of intense gamma-ray line emission from the Orion complex, attributed by Bloemen et al. to de-excitation of cosmic-ray carbon and oxygen nuclei, has important implications for emission from Orion in the infrared and in high-energy gamma-rays, and also for the theories of cosmic-ray origins. Some of these implications are briefly pointed out
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