More about tachyons

Abstract

“Anything that is not forbidden is compulsory,” says Murray Gell-Mann's half-facetious totalitarian principle. What then about faster-than-light particles called “tachyons”? In their May article Olexa-Myron Bilaniuk and E. C. George Sudarshan argued that valid solutions of Albert Einstein's relativity equations describe such particles. Thus if Einstein's equations are accurate descriptions of the physical universe and if solutions not forbidden are compulsory, tachyons must exist.

About an (Im‐)Possible Anomaly in Band Structure Theory

“…, we actually have to set a z ¼ b z ¼ 0, while a x ¼ b x ¼ Ài∇ x and a y ¼ b y ¼ Ài∇ y . Then the right-hand side of Equation ( 7) reproduces the radicand of Equation ( 6) twice as the two diagonal elements of a diagonal 2 Â 2 matrix in spinor space, and the formal square root will correspond to the operator ða ⋅ σÞ on the left-hand side of Equation (7). Thus, to take the formal square root of the differential operator related to Equation (6), one must automatically resort to a spinor picture, which has been largely popularized in the literature about graphene.…”

“…In their rather influential, but also highly debated article, Bilaniuk and Sudarshan suggested a general classification of elementary particles according to their energy-momentum relations. [7] Those are…”

“…As a tribute to a highly influential, but also highly debated article by Bilaniuk and Sudarshan, we call these band structures luxonic bands, tardyonic band, and tachyonic bands. [7] In Section 4, we will discuss possible realizations of these fundamental types of band structures and we will use realistic data to predict some of the expected experimental results. It will be obvious that luxonic and tardyonic band structures have already been described quite extensively in the past, but without identifying them as such.…”

Paradox-Free FTL Travel in Higher Dimensional Spaces

“…and Bilaniuk et al (1962 and1969) were among the first to propose the possibility of faster-thanlight (FTL) travel by swift entities called tachyons in the spacetime realm (4-D Minkowskian space) of Special Relativity (SR). These early FTL proposals were quickly objected to by investigators, such as Straud (1970) and Benford (1970), who held that FTL travel in some inertial frames could be perceived as backwards-in-time (BIT) travel (where effects precede causes) in other inertial frames.…”

Overcoming the Bradyon–Tachyon Barrier

“…Although there is still no experimental evidence for the existence of tachyons (or even experimental evidence that definitively proves their false physical reality), several researchers have been working to introduce this hypothetical particle into the modern quantum theory without compromising the foundations [4][5][6]. In particular, Surdashan, Binaliuk and Recami [7][8][9] have proved that, by introducing the reinterpretation principle and extending the theory of relativity to superluminal frames and objects, it is possible to solve the problem concerning the violation of the principle of causality that since the beginning has led physicists to consider the tachyon as a particle that is incompatible with physical reality [11][12].…”