arXiv subjects

M. Vasúth

Publications and source records attributed to M. Vasúth.

9 recordsLinked to original sources

arXiv2018

Long term measurements from the Mátra Gravitational and Geophysical Laboratory

Summary of the long term data taking, related to one of the proposed next generation ground-based gravitational detector's location is presented here. Results of seismic and infrasound noise, electromagnetic attenuation and cosmic muon radiation measurements are reported in the underground Matra Gravitational and Geophysical Laboratory near Gyöngyösoroszi, Hungary. The collected seismic data of more than two years is evaluated from the point of view of the Einstein Telescope, a proposed third generation underground gravitational wave observatory. Applying our results for the site selection will significantly improve the signal to nose ratio of the multi-messenger astrophysics era, especially at the low frequency regime.

astro-ph.IM↗

arXiv2018

Seismic noise measures for underground gravitational wave detectors

The selection of sites for underground gravitational wave detectors based on spectral and cumulative characterisation of the low frequency seismic noise. The evaluation of the collected long term seismological data in the Mátra Gravitational and Geophysical Laboratory revealed several drawbacks of the previously established characteristics. Here we demonstrate the problematic aspects of the recent measures and suggest more robust and more reliable methodology. In particular, we show, that the mode of the data is noisy, sensitive to the discretization and intrinsic averaging, and the $rms_{2Hz}$ is burdened by irrelevant information and not adapted to the technological changes. Therefore the use of median of the data instead of the mode and also the modification of the frequency limits of the $rms$ is preferable.

astro-ph.IM↗

arXiv2018

Silence measurements and measures for ET: characterisation of long term seismic noise in the Mátra Mountains

The analysis of long term seismological data collected underground in the Mátra Mountains, Hungary, using the facilities of the Mátra Gravitational and Geophysical Laboratory (MGGL) is reported. The laboratory is situated inside the Gyöngyösoroszi mine, Hungary, 88m below the surface. This study focuses on the requirements of the Einstein Telescope (ET), one of the planned third generation gravitational wave observatories, which is designed for underground operation. After a short introduction of the geophysical environment the evaluation of the collected long term data follows including the comparison of a two-week measurement campaign deeper in the mine. Based on our analysis and considering the specialities of long term data collection, refinements of the performance and evaluation criteria are suggested as well as performance estimation of a possible Mátra site.

astro-ph.IM↗

arXiv2017

First report of long term measurements of the {MGGL} laboratory in the {M}átra mountain range

Matra Gravitational and Geophysical Laboratory (MGGL) has been established near Gyöngyösoroszi, Hungary in 2015, in the cavern system of an unused ore mine. The Laboratory is located at 88~m below the surface, with the aim to measure and analyse the advantages of the underground installation of third generation gravitational wave detectors. Specialized instruments have been installed to measure seismic, infrasound, electromagnetic noise, and the variation of the cosmic muon flux. In the preliminary (RUN-0) test period, March-August 2016, data collection has been accomplished. In this paper we describe the research potential of the MGGL, list the installed equipments and summarize the experimental results of RUN-0. Here we report RUN-0 data, that prepares systematic and synchronized data collection of the next run period.

physics.ins-det↗

arXiv2015

Analytic description of SU(3) lattice thermodynamics in the whole temperature range within the mass gap approach

A general approach how to analytically describe and understand $SU(3)$ lattice thermodynamics in the whole temperature range $[0, \infty)$ is formulated and used. It is based on the effective potential approach for composite operators properly extended to non-zero temperature and density. This makes it possible to introduce into this general formalism the mass gap, which is responsible for the large-scale dynamical structure of the QCD ground state. The mass gap dependent gluon plasma pressure adjusted by this approach to the corresponding lattice data is shown to be a continuously growing function of temperature being thus differentiable in every point of its domain. At the same time, the entropy and energy densities have finite jump discontinuities at some characteristic temperature $T_c = 266.5 \ \MeV$ with latent heat $ε_{LH}= 1.41$. This is a firm evidence of the first-order phase transition in $SU(3)$ pure gluon plasma. The heat capacity has a $δ$-type singularity (an essential discontinuity) at $T_c$, so that the velocity of sound squared becomes zero at this point. All the independent thermodynamic quantities are exponentially suppressed below $T_c$ and rather slowly approach their respective Stefan-Boltzmann limits at high temperatures. Those thermodynamic quantities which are the ratios of their independent counterparts such as conformity, conformality and the velocity of sound squared approach their Stefan-Boltzmann limits rather rapidly and demonstrate a non-trivial dependence on the temperature below $T_c$. We also calculate the trace anomaly relation (the interaction measure) and closely related to it the gluon condensate, which are especially sensitive to the non-perturbative effects. An analytical description of the dynamical structure of $SU(3)$ gluon plasma is given.

hep-ph↗

arXiv2014

The Non-Perturbative Analytical Equation of State for SU(3) Gauge Theory

The effective potential approach for composite operators is generalized to non-zero temperature in order to derive the non-perturbative analytical equation of state for pure SU(3) Yang-Mills fields valid in the whole temperature range. Adjusting our parametrization of the gluon plasma pressure to the lattice pressure at high temperature for SU(3) Yang-Mills case, we have reproduced well our analytical curves and numbers not only for the pressure but for all other independent thermodynamic quantities as well in the whole temperature range $[0, \infty)$. We explicitly show that the pressure is a continuous function of the temperature across a phase transition at $T_c = 266.5 \MeV$. The entropy and energy densities have finite jump discontinuities at $T_c$ with latent heat $ε_{LH}= 1.414$. This is a firm evidence of the first-order phase transition in SU(3) pure gluon plasma. The heat capacity has a $δ$-type singularity (an essential discontinuity) at $T_c$, so that the velocity of sound squared becomes zero at this point. All the independent thermodynamic quantities are exponentially suppressed below $T_c$ and rather slowly approach their respective Stefan-Boltzmann limits at high temperatures. Those thermodynamic quantities which are the ratios of their independent counterparts such as conformity, conformality and the velocity of sound squared approach their Stefan-Boltzmann limit at high temperatures rather rapidly and demonstrate the non-trivial dependence on the temperature below $T_c$. We predict the existence of the three massive and the two massless excitations, all of non-perturbative dynamical origin. One of the massive excitations has an effective mass $1.17 \GeV$ and the two others have the same effective mass $0.585 \GeV$, but are propagating in different ways.

hep-ph↗

arXiv2010

The non-perturbative analytical equation of state for the gluon matter. I

The effective potential approach for composite operators has been generalized to non-zero temperatures in order to derive equation of state for the pure SU(3) Yang-Mills fields from first principles. In the absence of external sources it is nothing but the vacuum energy density. The key element of this derivation was an introduction of the temperature dependence into the expression for the Bag constant. Such obtained non-perturbative analytical equation of state for the gluon matter does not depend on the coupling constant, only the dependence on the mass gap, which is responsible for the large-scale structure of the QCD ground state, is present. The important thermodynamic quantities such as the pressure, energy and entropy densities, etc. have been calculated. We have shown explicitly that the pressure may continuously change its regime at $T_c=266.5 Mev$. All other thermodynamic quantities are to be understood to have drastic changes in their regimes at this point. The proposed analytical approach makes it possible to controll thermodynamics of the gluon matter at low temperatures below $T_c$ for the first time. We automatically reproduce the so-called "fuzy"-type bag models properties because of the mass gap explicit presence in our equation of state. We have also analytically calculated the NP gluon condensate as a function of temperature.

hep-ph↗

arXiv2007

Analytic approximations, perturbation methods, and their applications

The paper summarizes the parallel session B3 {\em Analytic approximations, perturbation methods, and their applications} of the GR18 conference. The talks in the session reported notably recent advances in black hole perturbations and post-Newtonian approximations as applied to sources of gravitational waves.

gr-qc↗

arXiv2003

Principal null directions of perturbed black holes

The properties of principal null directions of a perturbed black hole are investigated. It shown that principal null directions are directly observable quantities characterizing the space-time. A definition of a perturbed space-time, generalizing that given by Stewart and Walker is proposed. This more general framework allows one to include descriptions of a given space-time other than by a pair $(M,g)$ where $M$ is a four-dimensional differential manifold and $g$ a Lorentz metric. Examples of alternative characterizations are the curvature representation of Karlhede and others, the Newman-Penrose representation or observable quantities involving principal null directions. The conditions are studied under which the various alternative choices of observables provide equivalent descriptions of the space-time.

gr-qc↗