arXiv subjects

Andre Gsponer

Publications and source records attributed to Andre Gsponer.

44 records · Page 3Linked to original sources

arXiv2003

Depleted-Uranium Weapons: the Whys and Wherefores

The only military application in which depleted-uranium (DU) alloys out-perform present-day tungsten alloys is long-rod penetration into a main battle-tank's armor. However, this advantage is only on the order of 10%, and it disappears when the comparison is made in terms of actual lethality of complete anti-tank systems instead of laboratory-type steel penetration capability. Therefore, new micro- and nano-engineered tungsten alloys may soon out-perform DU alloys, enabling the production of tungsten munition which will be better than existing uranium munition, and whose overall life-cycle cost will be lower, due to the absence of the problems related to the radioactivity of uranium. The reasons why DU weapons have been introduced and used are analysed from the perspective that their radioactivity must have played an important role in the decision making process. It is found that DU weapons belong to the diffuse category of low-radiological-impact nuclear weapons to which emerging types of low-yield (i.e., fourth generation) nuclear explosives also belong. It is concluded that the battlefield use of DU during the 1991 Gulf War, which broke a 46-year-long taboo against the intentional use or induction of radioactivity in combat, has created a military and legal precedent which has trivialized the combat use of radioactive materials, and therefore made the use of nuclear weapons more probable.

physics.soc-ph↗

arXiv2003

Lanczos's equation as a way out of the spin 3/2 crisis?

It is shown (1) that Lanczos's quaternionic formulation of Dirac's equation does not lead to a solution of the problems that plague the standard spin 3/2 theory based on the Rarita-Schwinger equation, but (2) that the four-component solutions to the quaternionic generalization of Dirac's equation proposed by Lanczos in 1929 may provide a consistent theory for spin 3/2 particles, although at the cost of giving up the postulate that there should be a one-to-one correspondence between arbitrary-high-spin unitary representations of the inhomogeneous Lorentz group and elementary particles.

math-ph↗

arXiv2002

A comparison of delayed radiobiological effects of depleted-uranium munitions versus fourth-generation nuclear weapons

It is shown that the radiological burden due to the battlefield use of circa 400 tons of depleted-uranium munitions in Iraq (and of about 40 tons in Yugoslavia) is comparable to that arising from the hypothetical battle-field use of more than 600 kt (respectively 60 kt) of high-explosive equivalent pure-fusion fourth-generation nuclear weapons. Despite the limited knowledge openly available on existing and future nuclear weapons, there is sufficient published information on their physical principles and radiological effects to make such a comparison. In fact, it is shown that this comparison can be made with very simple and convincing arguments so that the main technical conclusions of the paper are undisputable -- although it would be worthwhile to supplement the hand calculations presented in the paper by more detailed computer simulations in order to consolidate the conclusions and refute any possible objections.

physics.med-ph↗

arXiv2002

Explicit closed-form parametrization of SU(3) and SU(4) in terms of complex quaternions and elementary functions

Remarkably simple closed-form expressions for the elements of the groups SU(n), SL(n,R), and SL(n,C) with n=2, 3, and 4 are obtained using linear functions of biquaternions instead of n x n matrices. These representations do not directly generalize to SU(n>4). However, the quaternion methods used are sufficiently general to find applications in quantum chromodynamics and other problems which necessitate complicated 3 x 3 or 4 x 4 matrix calculations.

math-ph↗

arXiv2002

On the "equivalence" of the Maxwell and Dirac equations

It is shown that Maxwell's equation cannot be put into a spinor form that is equivalent to Dirac's equation. First of all, the spinor ψin the representation \vec{F} = ψ\vec{u} \barψ of the electromagnetic field bivector depends on only three independent complex components whereas the Dirac spinor depends on four. Second, Dirac's equation implies a complex structure specific to spin 1/2 particles that has no counterpart in Maxwell's equation. This complex structure makes fermions essentially different from bosons and therefore insures that there is no physically meaningful way to transform Maxwell's and Dirac's equations into each other.

math-ph↗

arXiv2002

Comment on formulating and generalizing Dirac's, Proca's, and Maxwell's equations with biquaternions or Clifford numbers

Many difficulties of interpretation met by contemporary researchers attempting to recast or generalize Dirac's, Proca's, or Maxwell's theories using biquaternions or Clifford numbers have been encountered long ago by a number of physicists including Lanczos, Proca, and Einstein. In the modern approach initiated by Gursey, these difficulties are solved by recognizing that most generalizations lead to theories describing superpositions of particles of different intrinsic spin and isospin, so that the correct interpretation emerges from the requirement of full Poincare covariance, including space and time reversal, as well as of reversion and gauge invariance. For instance, the doubling of the number of solutions implied by the simplest generalization of Dirac's equation (i.e., Lanczos's equation) can be interpreted as isospin. In this approach, biquaternions and Clifford numbers become powerful opportunities to formulate the Standard Model of elementary particles, as well as many of its possible generalizations, in very elegant and compact ways.

math-ph↗

arXiv2002

Non-linear field theory for lepton and quark masses

Barut's formula for the mass of leptons is successfully extended to quarks. A very simple non-linear scalar field model explains both the N^4 power law dependence of the mass, and the existence of a cut-off which limits the number of leptons to three and the number of quarks to five, suggesting that the mass of the sixth quark is of different origin.

hep-ph↗

arXiv2002

Comment on "Deuterium--tritium fusion reactors without external fusion breeding" by Eliezer et al

Inclusion of inverse Compton effects in the calculation of deuterium-deuterium burn under the extreme conditions considered by Eliezer et al. [Phys. Lett. A 243 (1998) 298] are shown to decrease the maximum burn temperature from about 300 keV to only 100--150 keV. This decrease is such that tritium breeding by the DD --> T + p reaction is not sufficient to replace the small amount of tritium that is initially added to the deuterium plasma in order to trigger ignition at less than 10 keV.

physics.plasm-ph↗