Online research in philosophy

The cosmological constant problem arises at the intersection between general relativity and quantum field theory, and is regarded as a fundamental problem in modern physics. In this paper we describe the historical and conceptual origin of the cosmological constant problem which is intimately connected to the vacuum concept in quantum field theory. We critically discuss how the problem rests on the notion of physically real vacuum energy, and which relations between general relativity and quantum field theory are assumed in order to make the problem well-defined.

On Mass Problem in Relativistic Mechanics and Gravitational Physics Anatoli Vankov (dated 12.16.2003, e-mail: anatolivankov@hotmail.com) The proper mass of a test particle in General Relativity Theory (GRT) is a rest mass, so it is considered principally constant, just as in Kinematics of Special Relativity Theory (SRT). One may think that the same is true in SRT Mechanics (Dynamics). We found that a proper mass change occurs under a force action that is, during a transition from one inertial reference frame to another. The proper mass constancy in SRT Mechanics is, in fact, a weak field approximation leading to the Newtonian limit. We show that a variability of the proper mass is a fundamental physical phenomenon. It becomes especially important under strong field conditions, therefore, for understanding of the so-called self-energy divergence. The problem was seemingly overcome with help of the known renormalization procedure in Electrodynamics but not in gravitational field theory. GRT was shown to be nonrenormalizable. Our analysis of the SRT mass-energy concept showed that, after the proper mass variation was taken into account in SRT Mechanics equations, arguments for an exclusion of the gravity phenomenon from the SRT domain fell away. Moreover, this approach resulted in principal elimination of the gravitational divergence problem. Another new result concerned the speed of light. The conclusion was that the speed of light is not a fundamental physical constant: it is a physical quantity determined by a gravitational potential and has a cosmological meaning. In spite of radically different physical interpretation, the alternative approach to the gravitational problem gives an adequate description of “weak-field” gravitational experiments as GRT does: a numerical difference from GRT predictions is not meaningful. However, the difference in predictions progressively rises with field strength and an energy increase. One particular result concerns a behavior of a massive particle being in free fall in a gravitational field. In GRT, both a free particle and a photon, when approaching a gravitational center, tend to slow down, the particle speed being always less then the photon speed. In the SRT approach, the photon similarly slows down but not the particle. If so, superluminal particles exist. This is a new physical phenomenon, which may be called a gravitational refraction. We propose the experiment on the detection of superluminal particles in high-energy cosmic rays. It should be considered a new relativistic test having a falsifying power in a strong-field domain. This work is mainly conceptual. The purpose is to present in a simple form for a wide physical community some results of our study of Relativistic Mechanics, in which a source of a gravitational field is the proper mass. The main conclusion is that the development of the SRT-based divergence-free gravitation field theory is possible. PACS 04.80.Cc Key words: 1. General relativity

The cosmological constant problem arises at the intersection between general relativity and quantum field theory, and is regarded as a fundamental problem in modern physics. In this paper, we describe the historical and conceptual origin of the cosmological constant problem which is intimately connected to the vacuum concept in quantum field theory. We critically discuss how the problem rests on the notion of physically real vacuum energy, and which relations between general relativity and quantum field theory are assumed in order to make the problem well-defined.

The domains of quantum theory and general relativity overlap in situations where quantum mechanical effects cannot be ignored. In order to deal with this overlap of theoretical domains, there has been a tendency to apply the rules of quantum field theory to the classical gravitational field equations and without much regard for the implications of the whole enterprise. The gravitational version of the asymmetric ageing of identical biological specimens shows that (geometrically interpreted) curved spacetime is not dispensable. This result is used to conclude that the particle-based interpretations of quantum gravity are not acceptable.

The mutual conceptual incompatibility between General Relativity and Quantum Mechanics / Quantum Field Theory is generally seen as the most essential motivation for the development of a theory of Quantum Gravity. It leads to the insight that, if gravity is a fundamental interaction and Quantum Mechanics is universally valid, the gravitational field will have to be quantized, not at least because of the inconsistency of semi-classical theories of gravity. The objective of a theory of Quantum Gravity would then be to identify the quantum properties and the quantum dynamics of the gravitational field. If this means to quantize General Relativity, the general-relativistic identification of the gravitational field with the spacetime metric has to be taken into account. The quantization has to be conceptually adequate, which means in particular that the resulting quantum theory has to be background-independent. This can not be achieved by means of quantum field theoretical procedures. More sophisticated strategies, like those of Loop Quantum Gravity, have to be applied. One of the basic requirements for such a quantization strategy is that the resulting quantum theory has a classical limit that is (at least approximately, and up to the known phenomenology) identical to General Relativity. However, should gravity not be a fundamental, but an induced, residual, emergent interaction, it could very well be an intrinsically classical phenomenon. Should Quantum Mechanics be nonetheless universally valid, we had to assume a quantum substrate from which gravity would result as an emergent classical phenomenon. And there would be no conflict with the arguments against semi-classical theories, because there would be no gravity at all on the substrate level. The gravitational field would not have any quantum properties to be captured by a theory of Quantum Gravity, and a quantization of General Relativity would not lead to any fundamental theory. The objective of a theory of 'Quantum Gravity' would instead be the identification of the quantum substrate from which gravity results. The requirement that the substrate theory has General Relativity as a classical limit – that it reproduces at least the known phenomenology – would remain. The paper tries to give an overview over the main options for theory construction in the field of Quantum Gravity. Because of the still unclear status of gravity and spacetime, it pleads for the necessity of a plurality of conceptually different approaches to Quantum Gravity.

The possibility of a sub-quantum mechanical realm has been investigated in recent years by DeBroglie, Bohm, Vigier, and others. It is felt that what is needed in this investigation is some simple and direct resolution of the problem as to whether sub-quantum entities exist or not. By restricting attention to quanta of light energy there is presented a theoretical expression for a sub-quantum or micro-photon which has proven to be testable. It is possible by this development to bridge the particle-wave duality wherein these two conceptions become arithmetically commensurate with one another. The theoretical expression derived for the micro-photon also leads to a different interpretative approach to Planck's constant as well as the appearance of a new unit or element of mass.

A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. The results are then confirmed using the so-called dwell time definition of quantum tunnelling. I conclude with some remarks about the strong equivalence principle in quantum mechanics.

Diving into the nonlinear massive range of nuclear physics, the quark model already indicates that the linearized massless length scales break down. Although we are often confronted with nonlinear and relativistic dynamics, we obtain our fundamental values with the classical linear system of units SI by linear extrapolation. Ignoring the correspondent nonlinear relations while extrapolating to the Planck scale h=c=µ=1 based on linear massless relations leads to pseudo-scales equivalent to geometrized mass units. This paper shows that one of the fundamental dimensions length, time, mass becomes redundant approaching the Planck scale. The hidden information can be assigned to a geometrized natural quantum mass unit µ part of the Planck constant h. In other words: c, h, and µ are interrelated.

0.138% above the neutron and 0.276% above the proton baryon mass a natural mass unit µ can be identified by extrapolating dimensionless Planck units h=c=1 to the System of Units (SI). Similar to quantum measurements that determine h it is only necessary to relate the unit kinetic particle energy to the quantum energy of a photon having a unit wavelength. Connecting both energies and shifting the units, the inverse ratio of length units evolves proportional to the square of velocity units since both are proportional to the energy unit. With this connection the measurement of h becomes an indirect light velocity measurement and measurement of µ and shows that nonzero action and mass quanta corresponds to a finite light velocity c. As already shown, these sequential baryon mass differences (typical mass deficits of strong interaction) including the electron mass can be recovered within measurement error (some ppm) by simple relations obtained from bosonizing a massive Dirac equation.

In this paper a self-excited Rayleigh-type system models the auto-parametric wave-soliton coupling via phase fluctuations. The parameter of dissipative terms determine not only the most likely quantum coupling between solitons and linear waves but also the most likely mass of the solitons. Phase fluctuations are mediated by virtual photons coupling at light-velocity in a permanent Compton scattering process. With a reference to the SI-units and proper scaling relations in length and velocity, the final result shows a highly interesting sequence: the likely soliton Compton mass is about 1.00138 times the neutron and 1.00276 times the proton mass.