885 research outputs found
Estimated absorption of 136 mc/s satellite radio signals Interim technical report no. 1
Auroral, polar cap, and sudden cosmic noise absorption estimates for 136 mc/s satellite radio signa
Radiation Information from 1958 δ2
The telemetered radiation information from the satellite 1958 δ2
(Sputnik III) has been analyzed for sixty-two separate passes recorded
in College, Alaska. The data indicate a dependence of radiation intensity
on altitude in the range 250-500 km. Both the high and low
energy components apparently contribute to the overall increase of
intensity with altitude, but the presence of a continuous afterglow
in the scintillating crystal prevented detailed interpretation of the
results.IGY Project No. 32.42
NSF Grant No. Y/32.42/268Ye
Theory of phase-locking in generalized hybrid Josephson junction arrays
A recently proposed scheme for the analytical treatment of the dynamics of
two-dimensional hybrid Josephson junction arrays is extended to a class of
generalized hybrid arrays with ''horizontal'' shunts involving a capacitive as
well as an inductive component. This class of arrays is of special interest,
because the internal cell coupling has been shown numerically to favor in-phase
synchronization for certain parameter values. As a result, we derive limits on
the circuit design parameters for realizing this state. In addition, we obtain
formulas for the flux-dependent frequency including flux-induced switching
processes between the in-phase and anti-phase oscillation regime. The treatment
covers unloaded arrays as well as arrays shunted via an external load.Comment: 24 pages, REVTeX, 5 Postscript figures, Subm. to Phys. Rev.
Anti-phase locking in a two-dimensional Josephson junction array
We consider theoretically phase locking in a simple two-dimensional Josephson
junction array consisting of two loops coupled via a joint line transverse to
the bias current. Ring inductances are supposed to be small, and special
emphasis is taken on the influence of external flux. Is is shown, that in the
stable oscillation regime both cells oscillate with a phase shift equal to
(i.e. anti-phase). This result may explain the low radiation output
obtained so far in two-dimensional Josephson junction arrays experimentally.Comment: 11 pages, REVTeX, 1 Postscript figure, Subm. to Appl. Phys. Let
Regular and Irregular Boundary Conditions in the AdS/CFT Correspondence
We expand on Klebanov and Witten's recent proposal for formulating the
AdS/CFT correspondence using irregular boundary conditions. The proposal is
shown to be correct to any order in perturbation theory.Comment: 7 pages, typos correcte
Strong first order electroweak phase transition in the CP-conserving 2HDM revisited
The discovery of the Higgs boson by the LHC experiments ATLAS and CMS has marked a milestone for particle physics. Yet, there are still many open questions that cannot be answered within the Standard Model (SM). For example, the generation of the observed matter-antimatter asymmetry in the universe through baryogenesis can only be explained qualitatively in the SM. A simple extension of the SM compatible with the current theoretical and experimental constraints is given by the 2-Higgs-Doublet Model (2HDM) where a second Higgs doublet is added to the Higgs sector. We investigate the possibility of a strong first order electroweak phase transition in the CP-conserving 2HDM type I and type II where either of the CP-even Higgs bosons is identified with the SM-like Higgs boson. The renormalisation that we apply on the loop-corrected Higgs potential allows us to efficiently scan the 2HDM parameter space and simultaneously take into account all relevant theoretical and up-to-date experimental constraints. The 2HDM parameter regions found to be compatible with the applied constraints and a strong electroweak phase transition are analysed systematically. Our results show that there is a strong interplay between the requirement of a strong phase transition and collider phenomenology with testable implications for searches at the LHC
Instabilities in Josephson Ladders with Current Induced Magnetic Fields
We report on a theoretical analysis, consisting of both numerical and
analytic work, of the stability of synchronization of a ladder array of
Josephson junctions under the influence of current induced magnetic fields.
Surprisingly, we find that as the ratio of the mutual to self inductance of the
cells of the array is increased a region of unstable behavior occurs followed
by reentrant stable synchronization. Analytic work tells us that in order to
understand fully the cause of the observed instabilities the behavior of the
vertical junctions, sometimes ignored in analytic analyses of ladder arrays,
must be taken into account.Comment: RevTeX, 4 pages, 3 figure
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