scholarly journals Stochastic locality and master-field simulations of very large lattices

2018 ◽  
Vol 175 ◽  
pp. 01002 ◽  
Author(s):  
Martin Lüscher
Keyword(s):  
Gauge Theory ◽  
Lattice Qcd ◽  
Field Theories ◽  
Expectation Values ◽  
Mass Gap ◽  
Large Lattice ◽  
Technical Issues ◽  
The Subject ◽  
Local Observables

In lattice QCD and other field theories with a mass gap, the field variables in distant regions of a physically large lattice are only weakly correlated. Accurate stochastic estimates of the expectation values of local observables may therefore be obtained from a single representative field. Such master-field simulations potentially allow very large lattices to be simulated, but require various conceptual and technical issues to be addressed. In this talk, an introduction to the subject is provided and some encouraging results of master-field simulations of the SU(3) gauge theory are reported.

scholarly journals Some comments on infinities on quantum field theory: A functional integral approach

2016 ◽  
Vol 24 (2) ◽  
Author(s):  
Luiz C. L. Botelho
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Function Space ◽  
Functional Integral ◽  
Field Theories ◽  
Integral Approach ◽  
Quantum Field ◽  
Functional Integrals ◽  
Euclidean Field ◽  
The Subject

AbstractWe analyze on the formalism of probabilities measures-functional integrals on function space the problem of infinities on Euclidean field theories. We also clarify and generalize our previous published studies on the subject.

Conformal Field Theory of Free Bosonic and Fermionic Fields

2020 ◽  
pp. 443-475
Author(s):  
Giuseppe Mussardo
Keyword(s):  
Field Theories ◽  
Majorana Fermion ◽  
Partition Functions ◽  
Conformal Field Theories ◽  
Bosonic Field ◽  
Conformal Field ◽  
Mathematical Identities ◽  
Modular Transformations ◽  
Fermionic Fields ◽  
The Subject

Free theories are usually regarded as trivial examples of quantum systems. This chapter proves that this is not the case of the conformal field theories associated to the free bosonic and fermionic fields. The subject is not only full of beautiful mathematical identities but is also the source of deep physical concepts with far reaching applications. Chapter 12 also covers quantization of the bosonic field, vertex operators, the free bosonic field on a torus, modular transformations, the quantization of the free Majorana fermion, the Neveu–Schwarz and Ramond sectors, fermions on a torus, calculus for anti-commuting quantities and partition functions.

scholarly journals Expectation values of local fields in the Bullough-Dodd model and integrable perturbed conformal field theories

1998 ◽  
Vol 516 (3) ◽  
pp. 652-674 ◽  
Author(s):  
Vladimir Fateev ◽  
Sergei Lukyanov ◽  
Alexander Zamolodchikov ◽  
Alexei Zamolodchikov
Keyword(s):  
Local Fields ◽  
Field Theories ◽  
Conformal Field Theories ◽  
Expectation Values ◽  
Conformal Field

ON THE WAY TOWARDS INCREASING THE PREDICTIVE POWER OF THE NUCLEAR MEAN FIELD THEORIES: EVALUATION OF TWO-BODY MATRIX ELEMENTS

2012 ◽  
Vol 21 (05) ◽  
pp. 1250037
Author(s):  
HERVÉ MOLIQUE ◽  
JERZY DUDEK
Keyword(s):  
Inverse Problem ◽  
Predictive Power ◽  
Mean Field ◽  
Field Theories ◽  
Matrix Elements ◽  
The Matrix ◽  
Ill Posed ◽  
Technical Issues ◽  
Numerical Precision ◽  
Mean Field Theories

In this paper we collect a number of technical issues that arise when constructing the matrix representation of the most general nuclear mean field Hamiltonian within which "all terms allowed by general symmetries are considered not only in principle but also in practice". Such a general posing of the problem is necessary when investigating the predictive power of the mean field theories by means of the well-posed inverse problem. [J. Dudek et al., Int. J. Mod. Phys. E21 (2012) 1250053]. To our knowledge quite often ill-posed mean field inverse problems arise in practical realizations what makes reliable extrapolations into the unknown areas of nuclei impossible. The conceptual and technical issues related to the inverse problem have been discussed in the above-mentioned topic whereas here we focus on "how to calculate the matrix elements, fast and with high numerical precision when solving the inverse problem" [For space-limitation reasons we illustrate the principal techniques on the example of the central interactions].

scholarly journals Active engagement with stigmatised communities through digital ethnography

2016 ◽  
Vol 16 (6) ◽  
pp. 701-719 ◽  
Author(s):  
Monica J Barratt ◽  
Alexia Maddox
Keyword(s):  
Knowledge Production ◽  
Data Security ◽  
Active Engagement ◽  
Diverse Range ◽  
Digital Ethnography ◽  
Legal Challenges ◽  
Digital Environments ◽  
Technical Issues ◽  
The Subject ◽  
Conducting Research

Conducting research in the rapidly evolving fields constituting the digital social sciences raises challenging ethical and technical issues, especially when the subject matter includes activities of stigmatised populations. Our study of a dark-web drug-use community provides a case example of ‘how to’ conduct studies in digital environments where sensitive and illicit activities are discussed. In this paper we present the workflow from our digital ethnography and consider the consequences of particular choices of action upon knowledge production. Key considerations that our workflow responded to include adapting to volatile field-sites, researcher safety in digital environments, data security and encryption, and ethical-legal challenges. We anticipate that this workflow may assist other researchers to emulate, test and adapt our approach to the diverse range of illicit studies online. In this paper we argue that active engagement with stigmatised communities through multi-sited digital ethnography can complement and augment the findings of digital trace analyses.

The Mass Gap of SU(2) Lattice Gauge Theory in 2+1 Dimensions

1999 ◽  
Vol 32 (3) ◽  
pp. 411-418
Author(s):  
Fang XiYan ◽  
Guo ShuoHong ◽  
Pan ZhiGang
Keyword(s):  
Gauge Theory ◽  
Lattice Gauge Theory ◽  
Mass Gap ◽  
Lattice Gauge

scholarly journals From scalar field theories to supersymmetric quantum mechanics

2017 ◽  
Vol 32 (12) ◽  
pp. 1750073 ◽  
Author(s):  
D. Bazeia ◽  
F. S. Bemfica
Keyword(s):  
Field Theory ◽  
Quantum Mechanics ◽  
Scalar Field ◽  
Field Model ◽  
Supersymmetric Quantum Mechanics ◽  
Field Theories ◽  
Quantum Mechanical ◽  
Scalar Field Theory ◽  
Scalar Field Model ◽  
The Subject

In this work, we report a new result that appears when one investigates the route that starts from a scalar field theory and ends on a supersymmetric quantum mechanics. The subject has been studied before in several distinct ways and here, we unveil an interesting novelty, showing that the same scalar field model may describe distinct quantum mechanical problems.

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