scholarly journals Wilson loop's phase transition probed by non-local observable

2018 ◽  
Vol 929 ◽  
pp. 58-68 ◽  
Author(s):  
Hui-Ling Li ◽  
Zhong-Wen Feng ◽  
Shu-Zheng Yang ◽  
Xiao-Tao Zu
Keyword(s):  
Phase Transition ◽  
Local Observable ◽  
Non Local

scholarly journals Hybrid Stars in the Framework of NJL Models

2017 ◽  
Vol 45 ◽  
pp. 1760026 ◽  
Author(s):  
Gustavo A. Contrera ◽  
Milva Orsaria ◽  
I. F. Ranea-Sandoval ◽  
Fridolin Weber
Keyword(s):  
Phase Transition ◽  
Quark Matter ◽  
Mean Field ◽  
Field Approximation ◽  
Hadronic Matter ◽  
High Mass ◽  
Mean Field Approximation ◽  
Soft Phase ◽  
Non Local ◽  
Hybrid Stars

We compute models for the equation of state (EoS) of the matter in the cores of hybrid stars. Hadronic matter is treated in the non-linear relativistic mean-field approximation, and quark matter is modeled by three-flavor local and non-local Nambu−Jona-Lasinio (NJL) models with repulsive vector interactions. The transition from hadronic to quark matter is constructed by considering either a soft phase transition (Gibbs construction) or a sharp phase transition (Maxwell construction). We find that high-mass neutron stars with masses up to [Formula: see text] may contain a mixed phase with hadrons and quarks in their cores, if global charge conservation is imposed via the Gibbs conditions. However, if the Maxwell conditions is considered, the appearance of a pure quark matter core either destabilizes the star immediately (commonly for non-local NJL models) or leads to a very short hybrid star branch in the mass-radius relation (generally for local NJL models).

scholarly journals Effects of Hadron-Quark Phase Transitions in Hybrid Stars within the NJL Model

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 425 ◽  
Author(s):  
Ignacio Ranea-Sandoval ◽  
Milva Orsaria ◽  
Germán Malfatti ◽  
Daniela Curin ◽  
Mauro Mariani ◽  
...  
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Temperature Limit ◽  
Hadronic Matter ◽  
Transition Diagram ◽  
Mean Field Model ◽  
Relativistic Mean Field ◽  
Non Local ◽  
Gibbs Formalism ◽  
Hybrid Stars

We study local and non-local Polyakov Nambu-Jona-Lasinio models and analyze their respective phase transition diagram. We construct hybrid stars using the zero temperature limit of the local and non-local versions of Nambu-Jona-Lasinio model for quark matter and the modern GM1(L) parametrization of the non-linear relativistic mean field model for hadronic matter. We compare our models with data from PSR J1614-2230 and PSR J0343+0432 and also from GW170817 and its electromagnetic counterpart GRB170817A and AT2017gfo. We study observational signatures of the appearance of a mixed phase as a result of modeling a phase transition that mimics the Gibbs formalism and compare the results with the sharp first-order phase transition obtained using the Maxwell construction. We also study in detail the g-mode associated with discontinuities in the equation of state, and calculate non-radial oscillation modes using relativistic Cowling approximation.

scholarly journals Large data limit for a phase transition model with the p-Laplacian on point clouds

2018 ◽  
Vol 31 (2) ◽  
pp. 185-231 ◽  
Author(s):  
R. CRISTOFERI ◽  
M. THORPE
Keyword(s):  
Phase Transition ◽  
Large Data ◽  
Point Clouds ◽  
Mathematical Tool ◽  
Ginzburg Landau ◽  
Data Points ◽  
Non Local ◽  
Γ Convergence ◽  
Double Well Potential ◽  
Objective Functional

The consistency of a non-local anisotropic Ginzburg–Landau type functional for data classification and clustering is studied. The Ginzburg–Landau objective functional combines a double well potential, that favours indicator valued functions, and the p-Laplacian, that enforces regularity. Under appropriate scaling between the two terms, minimisers exhibit a phase transition on the order of ɛ = ɛn, where n is the number of data points. We study the large data asymptotics, i.e. as n → ∝, in the regime where ɛn → 0. The mathematical tool used to address this question is Γ-convergence. It is proved that the discrete model converges to a weighted anisotropic perimeter.

scholarly journals Phase transitions in tensorial group field theories: Landau-Ginzburg analysis of models with both local and non-local degrees of freedom

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Luca Marchetti ◽  
Daniele Oriti ◽  
Andreas G. A. Pithis ◽  
Johannes Thürigen
Keyword(s):  
Field Theory ◽  
Phase Transition ◽  
Phase Transitions ◽  
Quantum Gravity ◽  
Compact Group ◽  
Large Volume ◽  
Degrees Of Freedom ◽  
Scalar Fields ◽  
Theory Approach ◽  
Non Local

Abstract In the tensorial group field theory approach to quantum gravity, the theory is based on discrete building blocks and continuum spacetime is expected to emerge from their collective dynamics, possibly at criticality, via a phase transition. On a compact group of fixed volume this can be expected to be only possible in a large-volume or thermodynamic limit. Here we show how phase transitions are possible in TGFTs in two cases: a) considering the non-local group degrees of freedom on a non-compact Lie group instead of a compact one (or taking a large-volume limit of a compact group); b) in models including ℝ-valued local degrees of freedom (that can be interpreted as discrete scalar fields, often used in this context to provide a matter reference frame). After adapting the Landau-Ginzburg approach to this setting of mixed local/non-local degrees of freedom, we determine the critical dimension beyond which there is a Gaussian fixed point and a continuous phase transition which can be described by mean-field theory. This is an important step towards the realization of a phase transition to continuum spacetime in realistic TGFT models for quantum gravity.

Toward High-Resolution Low-Voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 218-219
Author(s):  
Zhifeng Shao
Keyword(s):  
Low Voltage ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Limiting Factor ◽  
Operating Voltage ◽  
Probe Radius ◽  
Non Local ◽  
Electron Microscopes ◽  
Image Position ◽  
Scanning Electron Microscopes

Recently, low voltage (≤5kV) scanning electron microscopes have become popular because of their unprecedented advantages, such as minimized charging effects and smaller specimen damage, etc. Perhaps the most important advantage of LVSEM is that they may be able to provide ultrahigh resolution since the interaction volume decreases when electron energy is reduced. It is obvious that no matter how low the operating voltage is, the resolution is always poorer than the probe radius. To achieve 10Å resolution at 5kV (including non-local effects), we would require a probe radius of 5∽6 Å. At low voltages, we can no longer ignore the effects of chromatic aberration because of the increased ratio δV/V. The 3rd order spherical aberration is another major limiting factor. The optimized aperture should be calculated as

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Sign in / Sign up

Export Citation Format

Share Document