arXiv subjects

M. Consoli

Publications and source records attributed to M. Consoli.

At least 37 records · Page 2Linked to original sources

arXiv2007

Is the physical vacuum a preferred frame ?

It is generally assumed that the physical vacuum of particle physics should be characterized by an energy momentum tensor in such a way to preserve exact Lorentz invariance. On the other hand, if the ground state were characterized by its energy-momentum vector, with zero spatial momentum and a non-zero energy, the vacuum would represent a preferred frame. Since both theoretical approaches have their own good motivations, we propose an experimental test to decide between the two scenarios.

hep-ph↗

arXiv2007

An easy reading of modern ether-drift experiments

Modern ether-drift experiments look for a preferred reference frame searching for modulations of the beat note of two optical resonators that might be induced by the Earth's rotation. We present a compact formalism to evaluate the signal for most experiments where two arbitrary gaseous media fill the resonating cavities. Our predictions can provide useful hints to optimize the experimental set up and the data taking.

physics.class-ph↗

arXiv2006

Is the standard singlet Higgs a true massive field ?

The phenomenon of spontaneous symmetry breaking admits a physical interpretation in terms of the Bose-condensation process of elementary spinless quanta. In a cutoff theory, this leads to a picture of the vacuum as a condensed medium whose excitations might deviate from exact Lorentz covariance in both the ultraviolet and infrared regions. For this reason, the conventional singlet Higgs boson, the shifted field of spontaneous symmetry breaking, rather than being a purely massive field, might possess a gapless branch describing the long-wavelength fluctuations of the scalar condensate. To test this idea, that might have substantial phenomenological implications, I compare with a detailed lattice simulation of the broken phase in the 4D Ising limit of the theory. The results are the following: i) differently from the symmetric phase, the single-particle energy spectrum is not reproduced by the standard massive form ii) for the value of the hopping parameter κ=0.076, increasing the lattice size from 20^4 to 32^4, the mass gap is found to decrease from the value 0.392(1) reported by Balog et al. (see Nucl. Phys. B714 (2005) 256) to the value 0.366(5). Both results confirm that, in the infrared region, the standard singlet Higgs cannot be considered as a simple massive field. Several arguments indicate that, approaching the continuum limit of the lattice theory, the observed volume dependence of the mass gap might require larger and larger lattice sizes before to show up.

hep-th↗

arXiv2006

Renormalization-Group flow for the field strength in scalar self-interacting theories

We consider the Renormalization-Group coupled equations for the effective potential V(ϕ) and the field strength Z(ϕ) in the spontaneously broken phase as a function of the infrared cutoff momentum k. In the k \to 0 limit, the numerical solution of the coupled equations, while consistent with the expected convexity property of V(ϕ), indicates a sharp peaking of Z(ϕ) close to the end points of the flatness region that define the physical realization of the broken phase. This might represent further evidence in favor of the non-trivial vacuum field renormalization effect already discovered with variational methods.

hep-th↗

arXiv2006

An effective vacuum refractive index from gravity and the present ether-drift experiments

Re-analyzing the data published by the Berlin and Duesseldorf ether-drift experiments, we have found a clean non-zero daily average for the amplitude of the signal. The two experimental values, A_0\sim (10.5 \pm 1.3) 10^{-16} and A_0\sim (12.1\pm 2.2) 10^{-16}$ respectively, are entirely consistent with the theoretical prediction (9.7\pm 3.5) 10^{-16} that is obtained once the Robertson-Mansouri-Sexl anisotropy parameter is expressed in terms of N_{vacuum}, the effective vacuum refractive index that one would get, for an apparatus placed on the Earth's surface, in a flat-space picture of gravity .

gr-qc↗

arXiv2006

Motion toward the Great Attractor from an ether-drift experiment

Since the end of 80's, the region of sky of galactic coordinates (l\sim 309^o, b\sim 18^o), corresponding to a declination γ\sim -44^o and right ascension α\sim 202^o, usually denoted as the "Great Attractor", is known to control the overall galaxy flow in our local Universe. In this sense, this direction might represent a natural candidate to characterize a hypothetical Earth's "absolute motion". Our analysis of the extensive ether-drift observations recently reported by an experimental group in Berlin provides values of αand γthat coincide almost exactly with those of the Great Attractor and not with the values γ\sim -6^o and α\sim 168^o obtained from a dipole fit to the anisotropy of the CMB. This supports in a new fashion the existence of a discrepancy between the observed motion of the Local Group and the direction obtained from the CMB dipole.

astro-ph↗

arXiv2005

Indications for a preferred reference frame from an ether-drift experiment

We present a fully model-independent analysis of the extensive observations reported by a recent ether-drift experiment in Berlin. No a priori assumption is made on the nature of a hypothetical preferred frame. We find a remarkable consistency with an Earth's cosmic motion exhibiting an average declination angle |γ|\sim 43^o and with values of the RMS anisotropy parameter (1/2-β+δ) that are one order of magnitude larger than the presently quoted ones. This might represent the first modern indication for a preferred frame and for a non-zero anisotropy of the speed of light.

gr-qc↗

arXiv2005

Evidence for an anisotropy of the speed of light

By comparing with the most recent experimental results, we point out the model dependence of the present bounds on the anisotropy of the speed of light. In fact, by replacing the CMB with a class of preferred frames that can better account for the experimental data, one obtains values of the RMS anisotropy parameter (1/2 -beta + delta) that are one order of magnitude larger than the presently quoted ones. The resulting non-zero anisotropy can be understood starting from the observation that the speed of light in the Earth's gravitational field is not the basic parameter c=1 entering Lorentz transformations. In this sense, light can propagate isotropically only in one `preferred' frame.

gr-qc↗

arXiv2005

Extra dimensions, preferred frames and ether-drift experiments

Models with extra space-time dimensions produce, tipically, a 4D effective theory whose vacuum is not exactly Lorentz invariant but can be considered a physical medium whose refractive index is determined by the gravitational field. This leads to a version of relativity with a preferred frame and to look for experimental tests with the new generation of ether-drift experiments using rotating cryogenic optical resonators. Considering various types of cosmic motion, we formulate precise predictions for the modulations of the signal induced by the Earth's rotation and its orbital revolution around the Sun. We also compare with recent experimental results that might represent the first modern experimental evidence for a preferred frame.

gr-qc↗

arXiv2005

Precision test for the new Michelson-Morley experiments with rotating cryogenic cavities

A new ether-drift experiment in Düsseldorf is currently measuring the relative frequency shift of two cryogenic optical resonators upon active rotations of the apparatus. I point out that the observed fractional amplitude of the sidereal variations of the signal in February, C_sid \sim (11 \pm 2) 10^{-16}, is entirely consistent with the expectations based on Miller's observations in the same epoch of the year. This leads to predict that, with future data collected in August-September, the observed sidereal variations should increase by \sim + 70 %, i.e. up to C_sid \sim (19\pm 2) 10^{-16} retaining the present normalization. This would represent clean experimental evidence for the existence of a preferred frame.

physics.class-ph↗

arXiv2005

Large logarithmic rescaling of the scalar condensate: a subtlety with substantial phenomenological implications

Lattice data, taken since 1998 near the critical line of a 4D Ising model, have been supporting the large logarithmic rescaling of the scalar condensate predicted in the alternative description of symmetry breaking proposed by Consoli and Stevenson. This conclusion has been challenged in a recent paper by Balog et al. In this paper we respond to the criticism of these authors, recapitulate the theoretical and numerical evidences in favour of the alternative interpretation of `triviality' and reiterate our conclusion: `triviality', by itself, cannot be used to place upper bounds on the Higgs boson mass.

hep-lat↗

arXiv2004

From classical to modern ether-drift experiments: the narrow window for a preferred frame

Modern ether-drift experiments look for a preferred frame by measuring the difference Δνin the relative frequencies of two cavity-stabilized lasers, upon local rotations of the apparatus or under the Earth's rotation. If the small deviations observed in the classical ether-drift experiments were not mere instrumental artifacts, by replacing the high vacuum in the resonating cavities with a dielectric gaseous medium (e.g. air), the typical measured Δν\sim 1 Hz should increase by orders of magnitude. This prediction is consistent with the characteristic modulation of a few kHz observed in the original experiment with He-Ne masers. However, if such enhancement would not be confirmed by new and more precise data, the existence of a preferred frame can be definitely ruled out.

physics.class-ph↗

arXiv2004

Large logarithmic rescaling of the scalar condensate: new lattice evidences

Using two different methods, we have determined the rescaling of the scalar condensate $Z\equiv Z_ϕ$ near the critical line of a 4D Ising model. Our lattice data, in agreement with previous numerical indications, support the behavior $Z_ϕ\sim \ln (Λ)$, $Λ$ being the ultraviolet cutoff. This result is predicted in an alternative description of symmetry breaking where there are no upper bounds on the Higgs boson mass from `triviality'.

hep-lat↗

arXiv2004

Old and new ether-drift experiments: a sharp test for a preferred frame

Motivated by the critical remarks of several authors, we have re-analyzed the classical ether-drift experiments with the conclusion that the small observed deviations should not be neglected. In fact, within the framework of Lorentzian Relativity, they might indicate the existence of a preferred frame relatively to which the Earth is moving with a velocity v_earth\sim 200$ km/s (value projected in the plane of the interferometer). We have checked this idea by comparing with the modern ether-drift experiments, those where the observation of the fringe shifts is replaced by the difference Δνin the relative frequencies of two cavity-stabilized lasers, upon local rotations of the apparatus or under the Earth's rotation. It turns out that, even in this case, the most recent data are consistent with the same value of the Earth's velocity, once the vacuum within the cavities is considered a physical medium whose refractive index is fixed by General Relativity. We thus propose a sharp experimental test that can definitely resolve the issue. If the small deviations observed in the classical ether-drift experiments were not mere instrumental artifacts, by replacing the high vacuum in the resonating cavities with a dielectric gaseous medium (e.g. air), the typical measured Δν\sim 1 Hz should increase by orders of magnitude. This expectation is consistent with the characteristic modulation of a few kHz observed in the original experiment with He-Ne masers. However, if such enhancement would not be confirmed by new and more precise data, the existence of a preferred frame can be definitely ruled out.

gr-qc↗

arXiv2003

The motion of the Solar System and the Michelson-Morley experiment

Historically, the Michelson-Morley experiment has played a crucial role for abandoning the idea of a preferred reference frame, the ether, and for replacing Lorentzian Relativity with Einstein's Special Relativity. However, our re-analysis of the Michelson-Morley original data, consistently with the point of view already expressed by other authors, shows that the experimental observations have been misinterpreted. Namely, the fringe shifts point to a non-zero observable Earth's velocity v_obs = 8.4 +/- 0.5 km/s. Assuming the existence of a preferred reference frame, and using Lorentz transformations to extract the kinematical Earth's velocity that corresponds to this v_obs, we obtain a real velocity, in the plane of the interferometer, v_earth = 201 +/- 12 km/s. This value is in excellent agreement with Miller's calculated value v_earth = 203 +/- 8 km/s and suggests that the magnitude of the fringe shifts is determined by the typical velocity of the Solar System within our galaxy. This conclusion, which is also consistent with the results of all other classical experiments, leads to an alternative interpretation of the Michelson-Morley type of experiments. Contrary to the generally accepted ideas of last century, they provide experimental evidence for the existence of a preferred reference frame. This point of view is also consistent with the most recent data for the anisotropy of the two-way speed of light in the vacuum.

astro-ph↗

arXiv2003

Quantum-hydrodynamical picture of the massive Higgs boson

The phenomenon of spontaneous symmetry breaking admits a physical interpretation in terms of the Bose-condensation process of elementary spinless quanta. In this picture, the broken-symmetry phase emerges as a real physical medium, endowed with a hierarchical pattern of scales, supporting two types of elementary excitations for k \to 0: a massive energy branch E_a(k) \to M_H, corresponding to the usual Higgs boson field, and a collective gap-less branch E_b(k) \to 0. This is similar to the coexistence of phonons and rotons in superfluid He-4 that, in fact, is usually considered the condensed-matter analog of the Higgs condensate. After previous work dedicated to the properties of the gap-less, phonon branch, in this paper we use quantum hydrodynamics to propose a physical interpretation of the massive branch. On the base of our results, M_H coincides with the energy-gap for vortex formation and a massive Higgs boson is like a roton in superfluid He-4. Within this interpretation of the Higgs particle, there is no "naturalness" problem since M_H remains a naturally intermediate, fixed energy scale, even for an ultimate ultraviolet cutoff Lambda \to \infty.

hep-ph↗

arXiv2003

Lattice measurement of the rescaling of the scalar condensate

We have determined the rescaling of the scalar condensate $Z\equiv Z_ϕ$ near the critical line of a 4D Ising model. Our lattice data, supporting previous numerical indications, confirm the behaviour $Z_ϕ\sim \ln ({\rm cutoff})$. This result is predicted in an alternative description of symmetry breaking where there are no upper bounds on the Higgs boson mass from `triviality'.

hep-ph↗

arXiv2003

The Michelson-Morley experiment and the cosmic velocity of the Earth

The Michelson-Morley experiment was designed to detect the relative motion of the Earth with respect to a preferred reference frame, the ether, by measuring the fringe shifts in an optical interferometer. These shifts, that should have been proportional to the square of the Earth's velocity, were found to be much smaller than expected. As a consequence, that experiment was taken as an evidence that there is no ether and, as such, played a crucial role for deciding between Lorentzian Relativity and Einstein's Special Relativity. However, according to some authors, the observed Earth's velocity was not negligibly small. To provide an independent check, we have re-analyzed the fringe shifts observed in each of the six different sessions of the Michelson-Morley experiment. They are consistent with a non-zero observable Earth's velocity $v_{\rm obs} = 8.4 \pm 0.5 km/s$. Assuming the existence of a preferred reference frame and using Lorentz transformations, this $v_{\rm obs}$ corresponds to a real velocity, in the plane of the interferometer, $v_{\rm earth} = 201 \pm 12 km/s$. This value, which is remarkably consistent with 1932 Miller's cosmic solution, suggests that the magnitude of the fringe shifts is determined by the typical velocity of the solar system within our galaxy. This conclusion is consistent with the results of all classical experiments (Morley-Miller, Illingworth, Joos, Michelson-Pease-Pearson,...) and with the existing data from present-day experiments.

physics.gen-ph↗