共查询到20条相似文献,搜索用时 31 毫秒
1.
We consider cosmic microwave background (CMB) anisotropy in models with quintessence, taking into account isocurvature fluctuation. It is shown that, if the primordial fluctuation of the quintessence has a correlation with the adiabatic density fluctuations, the CMB angular power spectrum C(l) at low multipoles can be suppressed without affecting C(l) at high multipoles. A possible scenario for generating a correlated mixture of the quintessence and adiabatic fluctuations is also discussed. 相似文献
2.
The apparent alignment of the cosmic microwave background multipoles on large scales challenges the standard cosmological model. Scalar field inflation is isotropic and cannot account for the observed alignment. We explore the imprints, a non-standard spinor driven inflation would leave on the cosmic microwave background anisotropies. We show it is natural to expect an anisotropic inflationary expansion of the Universe which has the effect of suppressing the low multipole amplitude of the primordial power spectrum, while at the same time to provide the usual inflationary features. 相似文献
3.
A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences. 相似文献
4.
We investigate a possible connection between the suppression of the power at low multipoles in the cosmic microwave background (CMB) spectrum and the late time acceleration. We show that, assuming a cosmic IR/UV duality between the UV cutoff and a global infrared cutoff given by the size of the future event horizon, the equation of state of the dark energy can be related to the apparent cutoff in the CMB spectrum. The present limits on the equation of state of dark energy are shown to imply an IR cutoff in the CMB multipole interval of 9>l>8.5. 相似文献
5.
The longitudinal response function of 4He is calculated with the Argonne V18 potential. The comparison with experiment suggests the need of a three-body force. When adding the Urbana IX three-body potential in the calculation of the lower longitudinal multipoles, the total strength is suppressed in the quasi-elastic peak, towards the trend of the experimental data. 相似文献
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7.
A. Ya. Silenko 《Russian Physics Journal》1991,34(7):607-611
It is shown that current electric multipoles exist. Their field is electrostatic and it is unrelated to the existence of a net electric charge. At long range, it is the same as the field of the corresponding charge electric multipoles. Current electric multipoles arise during the motion of magnetic multipoles. An orbital motion of magnetic dipoles, a precession of a current-carrying loop, and the motion of magnetic quadrupoles all lead to current electric quadrupole moments. Expressions for the current electric quadrupole moments of atoms and nuclei are derived.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 53–58, July, 1991.The author wishes to thank S. A. Kuten' and V. I. Rapoport for useful comments offered during the writing of this paper and for a discussion of the results. 相似文献
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A current responsible for the absorption of charged particles from complex nuclei is defined in such a way that the continuity equation is valid also in the presence of a complex potential. Then the long wave-length limit is derived for the multipoles of the radiation of this current using only general arguments. In particular it is shown that if the potential is spherically symmetric all the magnetic multipoles are zero in this limit. 相似文献
10.
Kazantsev 《Russian Physics Journal》1999,42(10):916-921
Concepts of spherical magnetic multipoles that represent distributions of electric currents over a spherical surface are introduced.
Vector potentials of magnetic multipoles meet solenoidal- and harmonic-field conditions outside of the spherical surface and
are continuous on it. Within the sphere, the vector potential of currents flowing outside of it is represented by the sum
of vector potentials of basis magnetic multipoles with coefficients expressed by spherical multipole moments of system of
currents. This expansion of the vector potential is in many respects analogous to the multipole expansion known from electrostatics.
The first three terms of the expansion represent components of the well-known magnetic moment, the next five terms represent
components of the magnetic quadrupole moment, etc. Possible applications of the magnetic spherical multipole technique are
discussed.
Krasnoyarsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 66–72, October,
1999. 相似文献
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Complex electric potentials and energy relations for shielded point charges and point multipoles of any arbitrary orders are
derived. It is demonstrated that both the complex electric potentials of shielded point multipoles and their interaction energies
can be expressed through derivatives of the Green’s complex function. As an example, relations for the complex potentials
of point multipoles of all orders in a half-plane are presented. It is indicated that the mathematical apparatus of shielded
point multipoles can be used, in particular, for successive refinement of estimates of the shielded conductor capacitance.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 81–87, December, 2007. 相似文献
13.
A. A. Shatskiy I. D. Novikov L. N. Lipatova 《Journal of Experimental and Theoretical Physics》2013,116(6):904-910
The motion of electric charges and dipoles falling radially and freely into a Schwarzschild black hole is considered. The inverse effect of the electromagnetic fields on the black hole is neglected. Since the dipole is assumed to be a point particle, the deformation due to the action of tidal forces on it is neglected. According to the theorem stating that “black holes have no hair”, the multipole electromagnetic fields should be completely radiated as a multipole falls into a black hole. The electromagnetic radiation power spectrum for these multipoles (a monopole and a dipole) has been found. Differences have been found in the spectra for different orientations of the falling dipole. A general method has been developed to find the radiated multipole electromagnetic fields for multipoles (including higher-order multipoles—quadrupoles, etc.) falling freely into a black hole. The calculated electromagnetic spectra can be compared with observational data from stellar-mass and smaller black holes. 相似文献
14.
P. Blunden 《Nuclear Physics A》1985,440(4):647-652
We investigate how the mechanisms of nuclear excitations and mesonic currents traditionally invoked to explain the quenching of low multipole magnetic transitions apply to higher spin operators. We find that there is a significant quenching of the low multipolarity spin-isospin operators by Δ-hole polarization, but that this effect decreases for higher multipoles. Conversely, the nucleon-hole polarization which has a negligible effect on low multipoles plays a predominant role in explaining the quenching of higher multipoles. Meson exchange currents provide a significant enhancement of the orbital operators but have only a slight effect on the spin components. 相似文献
15.
Krzysztof Bolejko 《General Relativity and Gravitation》2009,41(8):1737-1755
This paper presents the application of the Szekeres Swiss Cheese model to the analysis of observations of the cosmic microwave
background (CMB) radiation. The impact of inhomogeneous matter distribution on the CMB observations is in most cases studied
within the linear perturbations of the Friedmann model. However, since the density contrast and the Weyl curvature within
the cosmic structures are large, this issue is worth studying using another approach. The Szekeres model is an inhomogeneous,
non-symmetrical and exact solution of the Einstein equations. In this model, light propagation and matter evolution can be
exactly calculated, without such approximations as small amplitude of the density contrast. This allows to examine in more
realistic manner the contribution of the light propagation effect to the measured CMB temperature fluctuations. The results
of such analysis show that small-scale, non-linear inhomogeneities induce, via Rees-Sciama effect, temperature fluctuations
of amplitude 10−7–10−5 on angular scale ϑ < 0.24° (ℓ > 750). This is still much smaller than the measured temperature fluctuations on this angular scale. However, local and uncompensated
inhomogeneities can induce temperature fluctuations of amplitude as large as 10−3, and thus can be responsible the low multipoles anomalies observed in the angular CMB power spectrum. 相似文献
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In this Letter, I argue that a parity violating extension to general relativity can simultaneously explain the observed loss in power and provides a first step for explaining the alignment at a preferred axis (‘Axis of Evil’) in the low multipole moments of the WMAP data. This observational possibility also provides an experimental window for an inflationary leptogenesis mechanism arising from large-scale parity violation. Similar to the arguments of Contaldi, Peloso, Kofman and Linde, large scale power is suppressed from the backreaction of the parity violating term by inducing a velocity dependent potential. We also argue that this modification can supress power of odd parity multipoles on large scales, a pattern that is observed in the WMAP alignment anomaly. 相似文献
18.
Kinematics in Finsler space is used to study the propagation of ultra high energy cosmic rays particles through the cosmic microwave background radiation. We find that the GZK threshold is lifted dramatically in Randers-Finsler space. A tiny deformation of spacetime from Minkowskian to Finslerian allows more ultra-high energy cosmic rays particles to arrive at the earth. It is suggested that the lower bound of particle mass is related with the negative second invariant speed in Randers-Finsler space. 相似文献
19.
Kinematics in Finsler space is used to study the propagation of ultra high energy cosmic rays particles through the cosmic microwave background radiation. We find that the GZK threshold is lifted dramatically in Randers-Finsler space. A tiny deformation of spacetime from Minkowskian to Finslerian allows more ultra-high energy cosmic rays particles to arrive at the earth. It is suggested that the lower bound of particle mass is related with the negative second invariant speed in Randers-Finsler space. 相似文献