Photon Rest Mass Research Articles

Comment on a theorem about the effect of a finite photon rest mass

A theorem given by Goldhaber and Nieto states that the effect of a finite photon rest mass ..mu.. on observable electromagnetic fields is of the order (..mu..D)/sup 2/ where D is the dimension of the system. Though this theorem is undoubtedly correct, the derivation previously given seems to be of limited validity. We present here a different and more complete proof.

Astrophysical upper limits on the photon rest mass

The main ideas and methods currently used to obtain upper limits on the photon rest mass from astrophysical data are briefly reviewed. One method is based on the fact that if the photon has nonzero rest mass m magnetoacoustic waves cannot have frequencies lower than a certain critical frequency, which depends on m. If wisps in the Crab Nebula are interpreted as magnetoacoustic waves of extremely low frequency, then the data of many-year observations of the wisps put an upper limit on m which is much better than the one established under terrestrial conditions. An error is pointed out in a different method which has been proposed in the literature in which the contribution of the energy of the galactic magnetic field (or rather, the vector potential) to the mass of Galaxy is estimated on the basis of gravitational effects. The point is that in the general theory of relativity not only energy but also pressure has a weight. In the case under consideration, these two contributions cancel each other and the galactic magnetic field cannot produce anomalously strong gravitational fields. The most stringent upper limit on the photon rest mass, m? 3?10?60 g, is obtained from the analysis of the mechanical stability of magnetized gas in the galaxies with allowance for the specific pressure forces of the vector potential. This upper limit is 12 orders of magnitude better than the best upper limits obtained under terrestrial conditions. This result clearly demonstrates the effectiveness of astrophysical methods.

Astrofizicheskie verkhnie predely na massu pokoya fotona

Astrofizicheskie verkhnie predely na massu pokoya fotona

Improved Upper Limit on the Photon Rest Mass

It is shown that application of standard MHD arguments to hydromagnetic waves observed in the Crab Nebula dramatically improves the upper bound on photon rest mass. The standard argument that massive photons are governed by the Phoca field equations is outlined and applied to wisp features (identified as hydromagnetic waves) observed in the Crab. The results imply an upper limit for the photon rest mass of between 3 by 10 to the -54th power and 3 by 10 to the -53rd power gram, which is smaller than the best previous limits by a factor of 10,000 to 100,000. It is noted that although the present limit is probably valid in order of magnitude, some doubt remains since there are inconsistencies in the standard arguments.

Magnetohydrodynamic waves in the magnetosphere and the photon rest mass

Detailed measurements of the parameters of a shear Alfvén wave in the earth's magnetosphere have allowed a limit of ≲ 2.4 × 10−48 gm to be placed on the rest mass of the photon (Mph). This limit is comparable to that determined recently by Hollweg from statistical properties of Alfvén waves in the solar wind (≲1.3 × 10−48 gm) and, together, the two limits represent the best present upper limits to Mph as derived from measurements of magnetohydrodynamic waves.

Improved Limit on Photon Rest Mass

Improved Limit on Photon Rest Mass

Generalisation of Hubble's Law

RECENTLY, several new efforts to improve the upper bound on the possible rest mass (m0) of the photon have been made1–3. The theoretical basis is provided by Proca's equations1 (□ + μ2)AK = (4π/c)/JK (1) where charge is assumed conserved and μ = m0c/ħ. The bounds vary from 2 × 10−43 g to 3 × 10−56 g. As Yourgrau and Woodward4 point out, however, a finite mass is implicit in a ‘tired light’ interpretation of the cosmological redshift. When equation (1) is combined with Hubble's law5dν/dl = −Hν/c (2) it yields μ = H/2c and hence m0 < 10−63 g. Here ν is the photon frequency, l the distance traversed and H is Hubble's constant. In view of this limit a direct demonstration of the existence of a finite photon rest mass does not seem practical at present.

A photon rest mass and the mass of the universe

A photon rest mass and the mass of the universe

A photon rest mass and intergalactic magnetic fields

Conditions for the existence and stability of the currents which would be required to support an intergalactic magnetic field are examined to see what upper limit could be obtained for the photon rest mass if the existence of such a field is established.

A photon rest mass and the propagation of longitudinal electric waves in interstellar and intergalactic space

The author deals with the effect of a nonzero photon rest mass m on the propagation of longitudinal electric waves in a plasma for which the electrons are treated as a warm fluid with scalar pressure. The Proca equations are used to obtain a dispersion relation which describes two longitudinal wave types; when m=0, one wave type reduces to the usual electron acoustic wave while the second type, the Proca wave, ceases to exist. For frequencies away from resonance, the cold plasma model is approximately valid. Dispersion and absorption are discussed for frequencies both away from and near to resonance; particular attention is paid to Proca waves, and the possibilities of their travelling over interstellar and intergalactic distances are assessed.

A photon rest mass and electric currents in the Galaxy

Following an idea of Goldhaber and Nieto, conditions for the existence and stability of the currents which are required to support the observed galactic magnetic field are used to obtain an upper limit for the photon rest mass.

Difficulties concerning a Finite Photon Rest Mass

Pecker, Roberts and Vigier have suggested that much, if not all, of the cosmological redshift might be attributable to inelastic photon–photon scattering—if the photon possesses a finite rest-mass1. Pecker and Vigier have attempted (private communication) to apply Vigier's ideas to the electromagnetic propagation anomalies observed by Sadeh and others2,3. We agree in part with the ideas of Vigier and his co-workers, but their hypothesis, as regards these phenomena, cannot be completely correct as stated.

A photon rest mass and energy transport in cold plasmas

The energy densities and generalized Poynting vectors for longitudinal and transverse waves in cold plasmas are investigated.

Dependence of Doppler Shift on Photon Rest Mass

FOLLOWING renewed interest in the possible existence of a finite photon rest mass, Goldhaber and Nieto1 have presented an excellent review of the general methods which have been adopted in an attempt to establish an upper limit for this rest mass. At present the lowest upper limit obtained experimentally is µ0≤4×10−48 g (ref. 2), involving magnetic anomalies in the geomagnetic field. Suggestions have also been made1 on methods whereby an improved upper limit to µ0 may be determined. We present here a novel method for pursuing this goal based on a departure from the conventional Doppler shift for photons.

A photon rest mass and magnetic fields in the Galaxy

The effect of a photon rest mass on the dissipation of magnetic fields in the Galaxy is discussed and an upper limit on the rest mass is obtained: an earlier treatment is corrected and refined.

A photon rest mass and the absorption of longitudinal electric waves in interstellar space

The author treats the absorption of longitudinal electric waves in a cold plasma; upper limits for absorption in propagation from the galactic centre to the Earth are estimated.

A photon rest mass and the dispersion of longitudinal electric waves in interstellar space

Treats the propagation of longitudinal electric waves in a cold plasma, which can occur if the photon has a nonzero rest mass.

A photon rest mass and electromagnetic dispersion in cosmology

The effect of a photon rest mass on electromagnetic dispersion is calculated for the steady-state and Einstein-de Sitter cosmologies.

Concentric Spherical Cavities and Limits on the Photon Rest Mass

The concentric spherical cavity is used as a vehicle for study of the complete break-down of the relativistic particle in a box formula for the photon rest-mass effect. The results are applied to a determination of the limit on the photon's rest mass which can be inferred from the Schumann resonances.

Theoretical Interpretation of a Recent Experimental Investigation of the Photon Rest Mass

It is shown that both small-dimensional, extremely low-frequency resonant circuits and long coaxial cables are unsuited to the setting of significant limits on the photon rest mass.