Lifetime Constraints Research Articles

Top quark mass and Higgs mass limits in the standard SU(5) supergravity unification

Radiative breaking of the electroweal symmetry in the standard supergravity SU(5) model under the combined LEP and CDF constraints on the SUSY mass spectrum and under the proton lifetime constraint of Kamiokande is analyzed. The analysis gives an upper bound of 180 GeV for the top quark mass. The allowed domain of masses for the charged and the neutral Higgs are then determined for a given m t over the full allowed m t range. Domains of the Higgs mass accessible at LEP2 and at the SSC are delineated. It is shown that when τ(p→ g ̄ nK)>1.3X10 32 yr, then either a light CP even Higgs or a light chargino (or both) should be observable at LEP2.

Development of a high performance sorption refrigerator : L. Wade, J. Alvarez, P. Sywulka and E. Ryba Aerojet ElectroSystems, Azusa, CA 91702, USA

Although the main present cryogenic activity in ESTEC revolves around the preparation of ISO for launch in 1993, many other activities such as METEOSAT second generation, FIRST, GRASP, QUASAT and X-ray detection using bolometers all require some form of cooling to 80 K or less. Apart from the interest in all aspects involving the use of cryogenics in space, ESTEC, in an effort to overcome the major constraint of lifetime when using the solution of cryogens is currently involved in the study and development of two mechanical coolers for work in the temperature ranges of 80 and 4 K. These coolers are based on a Stirling cycle and were originally conceived by Oxford University and the Rutherford Laboratory in the UK for use on the shuttle launched Improved Stratospheric and Mesospheric Sounder (ISAMS). This paper will try to give an overview of ESTEC cryogenic interests with an emphasis on the above mechanical coolers.

Cryogenic activities at ESTEC

Although the main present cryogenic activity in ESTEC revolves around the preparation of ISO for launch in 1993, many other activities such as METEOSAT second generation, FIRST, GRASP, QUASAT and X-ray detection using bolometers all require some form of cooling to 80 K or less. Apart from the interest in all aspects involving the use of cryogenics in space, ESTEC, in an effort to overcome the major constraint of lifetime when using the solution of cryogens is currently involved in the study and development of two mechanical coolers for work in the temperature ranges of 80 and 4 K. These coolers are based on a Stirling cycle and were originally conceived by Oxford University and the Rutherford Laboratory in the UK for use on the shuttle launched Improved Stratospheric and Mesospheric Sounder (ISAMS). This paper will try to give an overview of ESTEC cryogenic interests with an emphasis on the above mechanical coolers.

Lifetime Constraints on Massive Neutrinos from Ultraviolet Observations of Clusters of Galaxies

Lifetime Constraints on Massive Neutrinos from Ultraviolet Observations of Clusters of Galaxies

The Effect of Interest-Rate Changes on Consumption Allocation over Time

TH-E INTrENTION OF TlHIS PAPER is to analyze the response of current and planned ruttire conistimption to expected increases or decreases in exogenous interest r-ates. OLlur analysis is based on examining the Slutsky equation formulation fromi the viewpoint of more than one nurmeraire. For two sets of periodsthose up to and including the earliest interest-rate change and those subsequent to the last-we show the following: The substitution effect on planned consuLMptioll is determinate in sign if the consumptions in each of these two sets of periods are not complementary to consumption in any periods outside the set itself. The sign of the income effect is generally indeterminate; it depends upon how one's lifetime constraint (and thus one's utility) is affected by the expected interest-rate changes. Based on our results, we describe an idealized experiment capable of refuting the model or, if the model is accepted as the maintained lhypothesis, capable of determining whose utility is increased or decreased by expected increases or decreases in interest rates. Our assumptions are the usual ones in the classical analysis of inter-temporal con-sumption optimization under subjective certainty [2, (115ff.)]. Non-asset income is exogenously determined, and there is subjective certainty about all the par-ameters of the model, non-asset income in every period, the planning horizon, and all present and futuLre prices, including the ex ante rates of interest. Our definitionis ar-e: