290,958 research outputs found
The Equivalence Principle in the Non-baryonic Regime
We consider the empirical validity of the equivalence principle for
non-baryonic matter. Working in the context of the TH\epsilon\mu formalism, we
evaluate the constraints experiments place on parameters associated with
violation of the equivalence principle (EVPs) over as wide a sector of the
standard model as possible. Specific examples include new parameter constraints
which arise from torsion balance experiments, gravitational red shift,
variation of the fine structure constant, time-dilation measurements, and
matter/antimatter experiments. We find several new bounds on EVPs in the
leptonic and kaon sectors.Comment: 22 pages, late
Flavor-oscillation clocks, continuous quantum measurements and a violation of Einstein equivalence principle
The relation between Einstein equivalence principle and a continuous quantum
measurement is analyzed in the context of the recently proposed
flavor-oscillation clocks, an idea pioneered by Ahluwalia and Burgard (Gen. Rel
Grav. Errata 29, 681 (1997)). We will calculate the measurement outputs if a
flavor-oscillation clock, which is immersed in a gravitational field, is
subject to a continuous quantum measurement. Afterwards, resorting to the weak
equivalence principle, we obtain the corresponding quantities in a freely
falling reference frame. Finally, comparing this last result with the
measurement outputs that would appear in a Minkowskian spacetime it will be
found that they do not coincide, in other words, we have a violation of
Einstein equivalence principle. This violation appears in two different forms,
namely: (i) the oscillation frequency in a freely falling reference frame does
not match with the case predicted by general relativity, a feature previously
obtained by Ahluwalia; (ii) the probability distribution of the measurement
outputs, obtained by an observer in a freely falling reference frame, does not
coincide with the results that would appear in the case of a Minkowskian
spacetime.Comment: 16 pages, accepted in Mod. Phys. Letts.
Analytic treatment of nuclear spin-lattice relaxation for diffusion in a cone model
We consider nuclear spin-lattice relaxation rate resulted from a diffusion
equation for rotational wobbling in a cone. We show that the widespread point
of view that there are no analytical expressions for correlation functions for
wobbling in a cone model is invalid and prove that nuclear spin-lattice
relaxation in this model is exactly tractable and amenable to full analytical
description. The mechanism of relaxation is assumed to be due to dipole-dipole
interaction of nuclear spins and is treated within the framework of the
standard Bloemberger, Purcell, Pound - Solomon scheme. We consider the general
case of arbitrary orientation of the cone axis relative the magnetic field. The
BPP-Solomon scheme is shown to remain valid for systems with the distribution
of the cone axes depending only on the tilt relative the magnetic field but
otherwise being isotropic. We consider the case of random isotropic orientation
of cone axes relative the magnetic field taking place in powders. Also we
consider the cases of their predominant orientation along or opposite the
magnetic field and that of their predominant orientation transverse to the
magnetic field which may be relevant for, e.g., liquid crystals. Besides we
treat in details the model case of the cone axis directed along the magnetic
field. The latter provides direct comparison of the limiting case of our
formulas with the textbook formulas for free isotropic rotational diffusion.
The dependence of the spin-lattice relaxation rate on the cone half-width
yields results similar to those predicted by the model-free approach.Comment: 29 p., 7 fig. arXiv admin note: substantial text overlap with
arXiv:1101.249
Is there a resting frame in the universe? A proposed experimental test based on a precise measurement of particle mass
According to the Special Theory of Relativity, there should be no resting
frame in our universe. Such an assumption, however, could be in conflict with
the Standard Model of cosmology today, which regards the vacuum not as an empty
space. Thus, there is a strong need to experimentally test whether there is a
resting frame in our universe or not. We propose that this can be done by
precisely measuring the masses of two charged particles moving in opposite
directions. If all inertial frames are equivalent, there should be no
detectable mass difference between these two particles. If there is a resting
frame in the universe, one will observe a mass difference that is dependent on
the orientation of the laboratory frame. The detailed experimental setup is
discussed in this paper.Comment: 9 pages, 4 figure
Against the realistic interpretation of the Theory of Relativity
The Theory of Relativity has been portrayed as a theory that redefined the way we look at the cosmos, enabling us to unlock the reality we live in. Its proponents are constantly reminding us of how Einstein managed to reveal the true nature of the universe with his groundbreaking theory, which has been proved multiple times until now. Yet, philosophy of science teaches us that no theory has any privileged connection with what we call reality per se. The role of science is to formulate models of the cosmos we see and not to try to interpret or reveal reality. This paper tries to show how this holds true even for the famous relativity theory, by showing specific objections to the connection of the theory with the Holy Grail of philosophers. By analyzing various subjects related to the theory, from the twins’ paradox to the GPS satellites, this paper illustrates that relativity is much less connected to reality than what we would like to think. At the end, what Einstein’s theory provides is nothing more than a way to formalize the interactions of the world but without being able to make any claims whatsoever regarding the ‘reality’ of its conclusions
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