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Related papers: Update on g-mode research

200 papers

In general relativity gravitational waves propagate at the speed of light, however in alternative theories of gravity that might not be the case. We study the effects of a modified speed of gravity, $c_T^2$, on the B-modes of the Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-11 Marco Raveri , Carlo Baccigalupi , Alessandra Silvestri , Shuang-Yong Zhou

We suggest that high-order g modes can be used as a probe of the internal magnetic field of SPB (slowly pulsating B) stars. The idea is based on earlier work by the authors which analytically investigated the effect of a vertical magnetic…

Astrophysics · Physics 2009-11-11 S. S. Hasan , J. -P. Zahn , J. Christensen-Dalsgaard

Since the last Amaldi meeting in 1997 we have learned that the r-modes of rapidly rotating neutron stars are unstable to gravitational radiation reaction in astrophysically realistic conditions. Newborn neutron stars rotating more rapidly…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Benjamin J. Owen

We study Hinode/SOT-FG observations of intensity fluctuations in Ca II H-line and G-band image sequences and their relation to simultaneous and co-spatial magnetic field measurements. We explore the G-band and H-line intensity oscillation…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. K. Lawrence , A. C. Cadavid

We have obtained empirical relations between the p-mode frequency shift and the change in solar activity indices. The empirical relations are determined on the basis of frequencies obtained from BBSO and GONG stations during solar cycle 22.…

Astrophysics · Physics 2015-06-24 Kiran Jain , S. C. Tripathy , A. Bhatnagar , B. Kumar

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\nu<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data.…

Astrophysics · Physics 2009-10-31 H. M. Antia , Sarbani Basu

We looked for signatures of Quasi-Biennial Periodicity (QBP) over different phases of solar cycle by means of acoustic modes of oscillation. Low-degree p-mode frequencies are shown to be sensitive to changes in magnetic activity due to the…

Solar and Stellar Astrophysics · Physics 2015-06-03 R. Simoniello , W. Finsterle , D. Salabert , R. A. García , S. Turck-Chièze , A. Jiménez , M. Roth

Context. Stellar internal magnetic fields have recently been shown to leave a detectable signature on period spacing patterns of gravity modes. Aims. We investigate the effect of the obliquity of a mixed (poloidal and toroidal) dipolar…

Solar and Stellar Astrophysics · Physics 2020-04-29 Vincent Prat , Stéphane Mathis , Coralie Neiner , Jordan Van Beeck , Dominic M. Bowman , Conny Aerts

We present a measurement of the $B$-mode polarization power spectrum of the cosmic microwave background anisotropies at 32 $\le$ $\ell$ $<$ 502 for three bands centered at 95, 150, and 220 GHz using data from the SPT-3G receiver on the…

We have used available intermediate degree p-mode frequencies for the solar cycle 23 to check the validity of previously derived empirical relations for frequency shifts (Jain et al.: 2000, Solar Phys., 192, 487). We find that the…

Astrophysics · Physics 2015-06-24 Kiran Jain , S. C. Tripathy , A. Bhatnagar

One of the most exciting quests in all of contemporary science is to find hints that in the first tiny fraction of a second after the Big-Bang the Universe hyper-inflated by a factor of \sim 10^{60}. Such inflation will have injected…

Instrumentation and Methods for Astrophysics · Physics 2012-09-14 C. Pryke

We consider a modified gravity theory through a special kind of ghost-free bimetric gravity, where one massive spin-2 field interacts with a massless spin-2 field. In this bimetric gravity, the late time cosmic acceleration is achievable.…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 Ajay Bassi , Bikash R. Dinda , Anjan A. Sen

We present a list of "best possible" estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this…

Solar and Stellar Astrophysics · Physics 2015-05-13 A-M. Broomhall , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. T. Fletcher , S. J. Hale , B. Miller , R. New

Accurate determination of the rotation rate in the radiative zone of the sun from helioseismic observations requires rotational frequency splittings of exceptional quality as well as reliable inversion techniques. We present here inferences…

Astrophysics · Physics 2009-11-13 A. Eff-Darwich , S. G. Korzennik , S. J. Jimenez-Reyes , R. A. Garcia

Frequencies of low-degree solar p modes are sensitive to activity over the entire Sun, including the unobservable far-side hemisphere. When frequency shifts extracted from week-long BiSON datasets are fitted to a linear combination of…

Solar and Stellar Astrophysics · Physics 2026-01-06 William J. Chaplin , Rachel Howe , Sarbani Basu , Yvonne Elsworth , Steven J. Hale , Emily J. Hatt , Eleanor Murray , Martin B. Nielsen

We study the effects of gravity waves, or g-modes, on hot extrasolar planets. These planets are expected to possess stably-stratified atmospheres, which support gravity waves. In this paper, we review the derivation of the equation that…

Earth and Planetary Astrophysics · Physics 2015-05-18 Chris Watkins , James Y-K. Cho

We have analysed VSOP (VLBI Space Observatory Programme) data at 5 GHz and ground-based VLBI (Very Long Baseline Interferometry) data at 15 GHz for the GHz-Peaked Spectrum (GPS) radio galaxy 2021+614. Its morphology is consistent with it…

We searched for an anisotropic background of gravitational waves using data from the LIGO S4 science run and a method that is optimized for point sources. This is appropriate if, for example, the gravitational wave background is dominated…

Astrophysics · Physics 2008-11-26 The LIGO Scientific Collaboration , B. Abbott

Although there are now some tentative signs that the start of cycle 24 has begun there is still considerable interest in the somewhat unusual behaviour of the current solar minimum and the apparent delay in the true start of the next cycle.…

Solar and Stellar Astrophysics · Physics 2010-03-23 Stephen Fletcher , Roger New , Anne-Marie Broomhall , William Chaplin , Yvonne Elsworth
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