Existence Of Tachyons Research Articles

Zipoy-Voorhees Gravitational Object as a Source of High-Energy Relativistic Particles

The Zipoy-Voorhees solution is known as the γ-metric and/or q-metric being static and axisymmetric vacuum solution of Einstein field equations which becomes strong curvature naked singularity. The metric is characterized by two parameters, namely, the mass M and the dimensionless deformation parameter γ. It is shown that the velocity of test particle orbiting around the central γ-object can reach the speed of light, consequently, the total energy of the particle will be very high for a specific value the deformation parameter of the spacetime. It is also shown that causality problem arises in the interior region of the physical singularity for the specific value of the deformation parameter when test particles can move with superluminal velocity being greater than the speed of light that might be an additional tool for explaining the existence of tachyons for γ>1/2 which are invisible for an observer.

A new quantum - relativistic model of tachyons

The possible existence of tachyons, namely hypothetical particles always moving faster than light in vacuum, is still controversial due to the common belief they would violate the principle of macroscopic causality, despite their existence is not forbidden, in principle, by the Einstein’s Special Theory of Relativity. Indeed, the main difficulties with tachyons are rather related to other two questions: their expected imaginary rest mass and the lack of a physical mechanism able to explain their existence especially from the standpoint of quantum theory. In this paper we discuss a novel physical mechanism, based on QED coherence in matter and on a reformulation of Special Theory of Relativity in the space-like region, able to explain a possible origin of tachyons as well as their real-value rest mass, ultimately related to the coherent dynamics of quantum vacuum.

The Relativistic Mechanic Theory of the String

In this article, a novel speculative method is used to derive the relativistic mechanic that governs the motion of the vibrating string within the compactified-dimensions spacetime. This mechanic claims that the relativistic mechanic of the special relativity should be only valid for the motion within the familiar four-dimensional spacetime. However, our novel mechanic is valid for the motion within the compactified-dimensions spacetime predicted by the string theory. The equations of this new mechanic show that the vibrating string can move within the compactified dimensions in a speed that is faster than light. It is also shown that this new relativistic mechanic goes to the classical Newtonian mechanic whenever the speed of the vibrating string is much less than the speed of light. Since the proposed mechanic does not prohibit the existence faster than light motion, it may uncover some of the mysteries regarding the string theory, such as the existence of tachyon and time travel. The main goal of this paper is to show that the motion within the compactified-dimensions spacetime obeys a different relativistic mechanic that will provide a startling and revolutionary perspective on the universe and answer some of the fundamental questions posed in the modern physics.

Tachyon Condensation and Brane Annihilation in Bose-Einstein Condensates: Spontaneous Symmetry Breaking in Restricted Lower-Dimensional Subspace

In brane cosmology, the Big Bang is hypothesized to occur by the annihilation of the brane–anti-brane pair in a collision, where the branes are three-dimensional objects in a higher-dimensional Universe. Spontaneous symmetry breaking accompanied by the formation of lower-dimensional topological defects, e.g. cosmic strings, is triggered by the so-called ‘tachyon condensation’, where the existence of tachyons is attributable to the instability of the brane–anti-brane system. Here, we discuss the closest analogue of the tachyon condensation in atomic Bose–Einstein condensates. We consider annihilation of domain walls, namely branes, in strongly segregated two-component condensates, where one component is sandwiched by two domains of the other component. In this system, the process of the brane annihilation can be projected effectively as ferromagnetic ordering dynamics onto a two-dimensional space. Based on this correspondence, three-dimensional formation of vortices from a domain-wall annihilation is considered to be a kink formation due to spontaneous symmetry breaking in the two-dimensional space. We also discuss a mechanism to create a ‘vorton’ when the sandwiched component has a vortex string bridged between the branes. We hope that this study motivates experimental researches to realize this exotic phenomenon of spontaneous symmetry breaking in superfluid systems.

Лев Яковлевич Штрум и гипотеза существования тахионов

Лев Яковлевич Штрум и гипотеза существования тахионов

The unification of inflation and late-time acceleration in the frame of k-essence

By using the formulation of the reconstruction, we explicitly construct models of k-essence, which unify the inflation in the early universe and the late accelerating expansion of the present universe by a single scalar field. Due to the higher derivative terms, the solution describing the unification can be stable in the space of solutions, which makes the restriction for the initial condition relaxed. The higher derivative terms also eliminate tachyon. Therefore we can construct a model describing the time development, which cannot be realized by a usual inflaton or quintessence models of the canonical scalar field due to the instability or the existence of tachyon. We also propose a mechanism of the reheating by the quantum effects coming from the variation of the energy density of the scalar field.

TACHYON DYNAMICS OF THE BLACK DISC LIMIT IN THE HARD SMALL x PROCESSES IN QCD

We investigate the effective field theory (EFT) which gives the approximate description of the scattering of two hard small dipoles in the small x processes in QCD near the black disc limit (BDL). We argue that the perturbative QCD approaches predict the existence of tachyon and visualize it in the approximation where α′P=0. We demonstrate that the high energy behavior of the cross-section depends strongly on the diffusion law in the impact parameter plane. On the other hand, almost threshold behavior of the cross section of the hard processes and multiplicities, i.e. fast increase of cross sections (color inflation), melting of ladders into color network and softening of the longitudinal distributions of hadrons are qualitatively insensitive to the value of diffusion in the impact parameter space. We evaluate α′P near the black disk limit and find significant α′P as the consequence of the probability conservation.

Tachyonic chaos and causality in the open universe

The chaoticity of classical world lines in extended Robertson-Walker cosmologies is pointed out and related to the fractal limit set of the covering group of the spacelike slices. We investigate the possible existence of tachyons (faster-than-light particles) in this context. The cosmic time and the 3-space co-ordinates comoving with the galactic background provide a distinguished frame of reference. With respect to this comoving frame the causality of tachyonic events can be unambiguously defined, contrary to Minkowski space. We study the dynamics of tachyons and show that tachyonic world-lines are chaotic in the center of the spacelike slices.

Motion of particles in five-dimensional Kaluza–Klein space–time

Study of radial and circular geodesics including those of tachyons in two spherically symmetric vacuum five-dimensional space–time is done. One of them is of Schwarzschild type and the other the so-called soliton solution. We obtain results which are different from the usual analogous four-dimensional (4D) ones. It is found that all the circular geodesics irrespective of whether they are timelike, null, or spacelike will be stable in the region r≳6M. It has also been shown that in a homogeneous cosmological model where the isotropic 3 space expands but the extra space contracts with time, the existence of tachyon is possible. This is in contradiction to the analogous 4D result obtained previously.

Do tachyons produce an unacceptable gravitational field?

The geodesics and the curvature of a metric representing an isolated tachyon are investigated. It is argued that the properties are unphysical and inconsistent with observation, thus providing further evidence against the existence of tachyons.

Indirect experimental evidence against the tachyons

It is noted that the empirically confirmed existence of the massiveW ± andZ 0 particles is in fact an indirect experimental evidence against the existence of tachyons.

On the existence of tachyons in a bradyon‐dominated universe

In the present paper, the question has been raised as to whether tachyons exist in our universe. The gravitational interaction of tachyons with bradyons is discussed by employing the method of geodesic deviation of a tachyon‐trajectory from a bradyon‐trajectory. It is noted that in certain cases, tachyons are attracted by bradyons, but in most cases they are repelled from bradyons. It is speculated that, due to their superluminal speed as well as gravitational repulsion, free tachyons would have fled out of this universe and inhabited a Meta‐Universe.

Tachyons and causal paradoxes

Although the existence of tachyons is not ruled out by special relativity, it appears that causal paradoxes will arise if there are tachyons. The usual solutions to these paradoxes employ some form of the reinterpretation principle. In this paper it is argued first that the principle is incoherent, second that even if it is not, some causal paradoxes remain, and third, the most plausible “solution,” which appeals to boundary conditions of the universe, will conflict with special relativity.

Synchronization in special relativity and related theories

The role of synchronization in special relativity and some related theories is investigated. It is found that physical reality can be described with any value on the synchronization parameter, that there exists a preferred inertial system and that the existence of tachyons or of waves travelling with velocity ≠ c relative to this system would enable us to measure « absolute » velocities. An asymmetry tachyonsbradyons is found.

Tachyons in an expanding universe

It has been suggested that causality problems associated with tachyons can be eliminated by the existence of a perferred frame of rest in which backward time travel is impossible. Furthermore, cosmology provides a de facto preferred rest frame. However, it is demonstrated here that the observed expansion of the universe raises further problems for the existence of tachyons.

Thought experiments at superluminal relative velocities

It is imagined that our world is being examined from a similar world which is moving relative to us with a velocity greater than that of light. The two worlds are supposed to be similar in that the particles in each appear to any observer in that world to have real measurable properties. However, the enormous relative velocity so distorts the observations that each world makes on the other that the squares of certain real quantities appear to the other observer to be negative. Neglect of this fact has led to the erroneous belief that a free charged tachyon would emit Cerenkov radiation and that the existence of tachyons would lead to logical paradoxes.

Tachyon behavior in theories with broken lorentz invariance

We consider questions relating to the production and detection of tachyons obeying one of the models of a non-Lorentz-invariant theory of tachyons developed in the preceding paper. We find one of these models to be promising, in that the existence of tachyons described by the model does not appear to contradict existing experiments, while it appears that the detection of such tachyons experimentally may be possible. The other models lead either to conflicts with experiment or to the implication that the existence of tachyons would be very difficult to observe.

Some theoretical and experimental aspects of the tachyon problem

In this paper, the hypothetical existence of tachyons is re-examined. It has previously been doubted whether tachyons would exist, for it can be shown with the space-time diagram used in the Special Theory of Relativity that they are moving backward in time for some moving systems, and this would contradict the principle of causality.

Peculiar Properties of Tachyon Signals

The gedanken experiment as introduced recently by Pirani to demonstrate the noncausal behavior of classical tachyons is reconsidered and analyzed in Minkowski space. Upon adhering to the principles used by Sudarshan and Feinberg with respect to the possible existence of tachyons, it is shown that the noncausal behavior of classical tachyons as deduced from this experiment is inconclusive.

On the existence of tachyons

Some dynamical properties of tachyons are investigated. It is concluded that tachyons do not interact with ordinary matter.