Inversion of magnetic dipole parameters using a scalar field gradiometer

We construct an inflation model on the Randall–Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two different approaches: in the first approach, the stabilizing field potential is directly appeared in the Friedmann equation and the resulting scenario is effectively a two-field inflation. In the second approach, the stabilization mechanism is considered in the context of a warp factor so that there is just one field present that plays the roles of both inflaton and stabilizer. We study constraints imposed on the model parameters from recent observations.

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Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽

10.1017/s003382220004087x ◽

1997 ◽

Vol 39 (1) ◽

pp. 27-32 ◽

Cited By ~ 40

Author(s):

John C. Vogel ◽

Joel Kronfeld

Keyword(s):

South Africa ◽

Magnetic Dipole ◽

Satisfactory Agreement ◽

Late Pleistocene ◽

Calibration Curve ◽

Dipole Field ◽

Radiocarbon Dates ◽

The Past ◽

The Earth ◽

Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

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CASIMIR EFFECT FOR THE ROBIN SURFACES IN STATIC ROBERTSON–WALKER SPACE–TIME

International Journal of Modern Physics D ◽

10.1142/s0218271811018767 ◽

2011 ◽

Vol 20 (02) ◽

pp. 161-168 ◽

Cited By ~ 1

Author(s):

MOHAMMAD R. SETARE ◽

M. DEHGHANI

Keyword(s):

Scalar Field ◽

Energy Momentum Tensor ◽

Casimir Effect ◽

Vacuum Expectation ◽

Robin Boundary Condition ◽

Momentum Tensor ◽

Space Time ◽

Conformally Invariant ◽

Time Space ◽

Robin Boundary

We investigate the energy–momentum tensor for a massless conformally coupled scalar field in the region between two curved surfaces in k = -1 static Robertson–Walker space–time. We assume that the scalar field satisfies the Robin boundary condition on the surfaces. Robertson–Walker space–time space is conformally related to Rindler space; as a result we can obtain vacuum expectation values of the energy–momentum tensor for a conformally invariant field in Robertson–Walker space–time space from the corresponding Rindler counterpart by the conformal transformation.

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