ORCID Profile
0000-0001-7086-8049
Current Organisations
Uppsala University
,
Swedish Institute of Space Physics
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Publisher: IOP Publishing
Date: 05-1986
Publisher: AIP Publishing
Date: 06-1980
DOI: 10.1063/1.524565
Abstract: Energy levels, normalization factors, quantal expectation values, and probability densities at the origin for nonrelativistic bound s states of the linear central potential are calculated by means of phase-integral formulas, given by N. Fröman in two recent papers. The accuracy of the phase-integral method is exhibited by a numerical comparison with exact results. During the last few years the potential in question has been widely used as a model potential describing quark confinement in heavy mesons.
Publisher: Springer Science and Business Media LLC
Date: 08-1999
DOI: 10.1007/BF02676857
Publisher: Elsevier BV
Date: 10-1985
Publisher: Springer Science and Business Media LLC
Date: 13-02-2011
DOI: 10.1038/NPHYS1907
Publisher: American Geophysical Union (AGU)
Date: 08-1989
Publisher: American Geophysical Union (AGU)
Date: 07-2011
DOI: 10.1029/2011JA016565
Publisher: Copernicus GmbH
Date: 31-01-2005
Abstract: Abstract. Experimental results from three ionospheric HF pumping experiments in overdense E or F regions are summarized. The experiments were conducted by the use of the EISCAT HF Heating facility located near Tromsø, Norway, allowing HF pumping the ionosphere in a near geomagnetic field-aligned direction. Distinctive features related to auroral activations in the course of the experiments are identified. Typical features observed in all experiments are the following: generation of scattered components in dynamic HF radio scatter Doppler spectra strong increase of ion temperatures Ti and local ionospheric electric field E0 modification of the auroral arc and local spiral-like formation. However, some effects were observed only when the HF pump wave was reflected from the F2 layer. Among them are the generation of intense field-aligned ion outflows, and a strong increase in the electron temperature Te with altitude. A possible scenario for the substorm triggering due to HF pumping into an auroral ionosphere is discussed. The authors present their interpretation of the data as follows. It is suggested that two populations of charged particles are at play. One of them is the runaway population of electrons and ions from the ionosphere caused by the effects of the powerful HF radio wave. The other is the population of electrons that precipitate from the magnetosphere. It is shown that the hydrodynamical equilibrium was disrupted due to the effects of the HF pumping. We estimate that the parallel electric field can reach values of the order of 30mV/m during substorm triggering.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2015
Publisher: American Geophysical Union (AGU)
Date: 10-1993
DOI: 10.1029/93JA01387
Publisher: Elsevier BV
Date: 04-2008
Publisher: American Geophysical Union (AGU)
Date: 12-1985
Publisher: Austrian Academy of Sciences Press
Date: 2011
DOI: 10.1553/PRE7S571
Publisher: American Physical Society (APS)
Date: 22-11-1982
Publisher: American Geophysical Union (AGU)
Date: 05-1990
Publisher: Wiley
Date: 21-01-2004
Publisher: IOP Publishing
Date: 1990
Publisher: Springer Science and Business Media LLC
Date: 02-2005
Publisher: American Geophysical Union (AGU)
Date: 12-1987
Publisher: American Geophysical Union (AGU)
Date: 09-1987
Publisher: American Geophysical Union (AGU)
Date: 15-03-1998
DOI: 10.1029/98GL00492
Publisher: American Physical Society (APS)
Date: 03-02-1997
Publisher: American Geophysical Union (AGU)
Date: 05-12-2007
DOI: 10.1029/2007GL031989
Publisher: American Geophysical Union (AGU)
Date: 11-1983
Publisher: IOP Publishing
Date: 11-2008
Publisher: Springer Science and Business Media LLC
Date: 09-1997
DOI: 10.1007/BF02676524
Publisher: IOP Publishing
Date: 12-2011
Publisher: American Geophysical Union (AGU)
Date: 05-1986
Publisher: Oxford University Press (OUP)
Date: 28-11-2020
Abstract: We present the first observational evidence that light propagating near a rotating black hole is twisted in phase and carries orbital angular momentum (OAM). This physical observable allows a direct measurement of the rotation of the black hole. We extracted the OAM spectra from the radio intensity data collected by the Event Horizon Telescope from around the black hole M87* by using wavefront reconstruction and phase recovery techniques and from the visibility litude and phase maps. This method is robust and complementary to black hole shadow circularity analyses. It shows that the M87* rotates clockwise with an estimated rotation parameter a = 0.90 ± 0.05 with an $\\sim 95{{\\ \\rm per\\ cent}}$ confidence level (c.l.) and an inclination i = 17° ± 2°, equivalent to a magnetic arrested disc with an inclination i = 163° ± 2°. From our analysis, we conclude that, within a 6σ c.l., the M87* is rotating.
Publisher: No publisher found
Date: 1999
DOI: 10.1029/1999JA900039
Publisher: American Geophysical Union (AGU)
Date: 10-1994
DOI: 10.1029/94JA01399
Publisher: American Physical Society (APS)
Date: 21-07-2021
Publisher: Springer Science and Business Media LLC
Date: 03-2006
Publisher: Copernicus GmbH
Date: 30-09-2002
DOI: 10.5194/ANGEO-20-1479-2002
Abstract: Abstract. Comparisons between bistatic scatter measurements and simulation results during the Tromsø HF pumping experiment on 16 February 1996 are made. Doppler measurements of an HF diagnostic signal scattered from the field-aligned irregularities (FAIs) in the auroral E-region were carried out on the London – Tromsø – St. Petersburg path at 9410 kHz from 21:00 to 22:00 UT. The scattered signals were observed both from natural and artificial ionospheric irregularities located in the vicinity of Tromsø. To simulate the Doppler frequency shifts, fd , of scattered signals, a radio channel model, named CONE, was developed. The model allows for ray tracing, group and phase paths, and Doppler frequency shift calculations. The calculated Doppler shifts were analyzed for dependence on the magnitude and direction of plasma velocities in the scattering volume. It was found that the velocity components in the north-south direction are crucial for explaining the Doppler frequency shifts of the scattered diagnostic signals. To simulate fd , real velocities obtained from the EISCAT UHF radar at an altitude of 278 km and from the digital all-sky imager during the experiment were employed. The simulation results of Doppler frequency shift variations with time are in reasonable agreement with the experimental Doppler shifts of scattered signals on the London – Tromsø – St. Petersburg path.Key words. Ionosphere (active experiments ionospheric irregularities) Radio science (ionospheric propagation)
Publisher: American Geophysical Union (AGU)
Date: 09-1984
Publisher: IEEE
Date: 05-2015
Publisher: American Geophysical Union (AGU)
Date: 23-04-1993
DOI: 10.1029/93GL00833
Publisher: American Geophysical Union (AGU)
Date: 1986
Publisher: American Physical Society (APS)
Date: 06-1992
Publisher: Wiley
Date: 09-02-2011
Publisher: The Optical Society
Date: 19-01-2012
DOI: 10.1364/OE.20.002445
Publisher: American Geophysical Union (AGU)
Date: 12-2001
DOI: 10.1029/2001JA900002
Publisher: American Geophysical Union (AGU)
Date: 10-2001
DOI: 10.1029/2001JA900004
Publisher: American Geophysical Union (AGU)
Date: 11-1983
Publisher: American Geophysical Union (AGU)
Date: 02-2008
DOI: 10.1029/2007JA012491
Publisher: American Geophysical Union (AGU)
Date: 03-2007
DOI: 10.1029/2006GL028948
Publisher: Elsevier BV
Date: 12-1982
Publisher: Elsevier BV
Date: 12-1985
Publisher: IEEE
Date: 05-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2010
Publisher: American Physical Society (APS)
Date: 06-11-2017
Publisher: American Physical Society (APS)
Date: 05-02-2014
Publisher: IOP Publishing
Date: 07-11-2012
Publisher: IOP Publishing
Date: 03-2012
Publisher: American Geophysical Union (AGU)
Date: 08-1988
Publisher: American Physical Society (APS)
Date: 08-05-2009
Publisher: American Physical Society (APS)
Date: 15-12-2005
Publisher: Elsevier BV
Date: 03-2010
Publisher: American Physical Society (APS)
Date: 27-02-2003
Publisher: Springer Science and Business Media LLC
Date: 05-1997
DOI: 10.1007/BF02676201
Publisher: American Physical Society (APS)
Date: 22-08-2007
Publisher: Springer Science and Business Media LLC
Date: 08-2016
Publisher: IOP Publishing
Date: 14-11-2007
Publisher: AIP Publishing
Date: 07-1976
DOI: 10.1063/1.523047
Abstract: The eigenvalue problem of the one-dimensional potential well V (X) =a‖X‖ is solved by means of certain higher-order phase-integral approximations. The purpose of this paper is to demonstrate numerically the applicability and accuracy of these approximations (which are related to, but not identical to, the higher-order JWKB approximations) and, therefore, a comparison is made with exact results. An upper bound for the absolute error in the first-order approximation is calculated analytically and found to be in accordance with the actual numerical results which are displayed in a table.
Publisher: American Physical Society (APS)
Date: 14-02-2007
Publisher: American Geophysical Union (AGU)
Date: 07-1985
Publisher: American Geophysical Union (AGU)
Date: 10-1990
Publisher: American Geophysical Union (AGU)
Date: 06-2015
DOI: 10.1002/2015RS005662
Publisher: American Geophysical Union (AGU)
Date: 12-1984
Publisher: Springer Science and Business Media LLC
Date: 1997
DOI: 10.1007/BF02677833
Publisher: Springer Science and Business Media LLC
Date: 05-1994
DOI: 10.1007/BF01045693
Publisher: IEE
Date: 2009
DOI: 10.1049/CP.2009.0038
Publisher: American Geophysical Union (AGU)
Date: 16-07-2010
DOI: 10.1029/2009RS004299
Publisher: IEE
Date: 2009
DOI: 10.1049/CP.2009.0078
Publisher: American Geophysical Union (AGU)
Date: 12-1995
DOI: 10.1029/95JA01631
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1007/BF02121457
Publisher: American Geophysical Union (AGU)
Date: 05-1989
Publisher: Elsevier BV
Date: 12-1997
Publisher: American Physical Society (APS)
Date: 09-03-2021
Publisher: Routledge
Date: 10-09-2012
Publisher: American Physical Society (APS)
Date: 09-2020
Publisher: American Physical Society (APS)
Date: 11-09-1989
Publisher: Springer Science and Business Media LLC
Date: 07-1999
DOI: 10.1007/BF02677560
Publisher: American Geophysical Union (AGU)
Date: 05-12-2007
DOI: 10.1029/2007GL030997
No related grants have been discovered for Bo Thidé.