Time reversal, fermion doubling, and the masses of lattice Dirac fermions in three dimensions

There can be few subjects that benefit more than binary stars do from complementary approaches. Consider their orbits, for an initial example. By ‘visual’ methods — by which I mean all methods of obtaining angular resolution on the sky, including the modern techniques of optical interferometry — one can determine an orbit, but with the scale known in terms of angular measure only. By spectroscopic (radial-velocity) methods one obtains the linear scale of the orbit, but with those techniques the inclination to the line of sight is indeterminate. In order to find the complete characteristics of the orbit in three dimensions — as is essential in order to find those most important data, the masses of the component stars — one needs to utilize both methods. It is, accordingly, clearly of great value to have a meeting like this that is object-oriented rather than technique-oriented; it is a long time since there was a meeting specifically devoted to binary stars, and especially in view of the great advances that have taken place in observational techniques of all sorts in recent years it is more than timely that we should have this meeting now. We are certainly very grateful to Dr. McAlister and his colleagues for arranging it and holding it at this beautiful venue.

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Time-Reversal Reconstructions of Clustered Sources and Diagnosis of Faulty Antenna Elements in Three Dimensions

2019 IEEE MTT-S International Microwave Symposium (IMS) ◽

10.1109/mwsym.2019.8701043 ◽

2019 ◽

Author(s):

Jing-Cheng Liang ◽

Zhizhang Chen ◽

Jun-Feng Wang ◽

Hua-Peng Zhao ◽

Cheng Peng ◽

...

Keyword(s):

Time Reversal ◽

Three Dimensions

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Dimensi Teks Berita Online Larangan Mudik 2021 di Tempo.com dan Kompas.com dalam Perspektif Teun A. Van Dijk

GHANCARAN: Jurnal Pendidikan Bahasa dan Sastra Indonesia ◽

10.19105/ghancaran.v3i1.4640 ◽

2021 ◽

Vol 3 (1) ◽

pp. 53-68

Author(s):

Hesty Kusumawati ◽

Roychan Yasin

Keyword(s):

Discourse Analysis ◽

Critical Discourse Analysis ◽

Negative Impact ◽

Three Dimensions ◽

Critical Discourse ◽

Analysis Techniques ◽

Global Coherence ◽

Rhetorical Studies ◽

The Media ◽

The Masses

In its role, the media is the conveyor of information through discourses that will influence the perception of the masses. The presentation of a news cannot be separated from the ideology of the media and media journalists. The choice of words used by journalists in a text shows how one's meaning of facts or reality is based on ideology. Critical discourse analysis is always interesting to study more deeply. Discourse by Van Dijk is described as having three dimensions or structures: text, social cognition, and social context. This study aims to describe the analysis of Van Dijk discourse in the text dimension of the news on the prohibition of going home in the media Tempo.com and Kompas.com. The approach used in this research is descriptive qualitative with note-taking techniques and Teun A. Van Dijk's discourse analysis techniques. The results showed three structures of the news text. The macro structure shows differences in global coherence, the first news is about the negative impact of policies while the second news is policy considerations. The superstructure consists of summaries and stories based on selected perspectives from global coherence. While in the micro structure there are semantic, syntactic, stylistic and rhetorical studies, the four studies also display the meaning of the background, details, intentions, presuppositions, and sentence building that supports the perspective of each news.

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Study of the Conditions Set by Unitarity and Time-Reversal Invariance in the ρ–ω Mixing with the Three-Body Mixing Formalism

Canadian Journal of Physics ◽

10.1139/p72-415 ◽

1972 ◽

Vol 50 (24) ◽

pp. 3198-3205

Author(s):

T. T. Gien

Keyword(s):

Experimental Data ◽

Vector Meson ◽

Time Reversal ◽

Relative Phase ◽

Decay Rates ◽

Time Reversal Invariance ◽

Reversal Invariance ◽

The Masses ◽

Three Body ◽

Mixing Problem

Using the three-body interference formalisms recently developed by us, we study the conditions imposed by time-reversal invariance and unitarity on the relative phase and strength of the ρ–ω mixing in the presence of vector meson [Formula: see text]. It is found that the effect of vector meson [Formula: see text] on these conditions when they are compared to those obtained with the usual two-body interference formalisms is very small. Even if the width of [Formula: see text] was ten times larger than the actual one, still this effect would be negligible. Thus, this detailed analysis confirms again the possibility of neglecting the effect of [Formula: see text] in the ρ–ω mixing problem. All the conclusions reached by us in this study are based purely on the experimental data alone and thereby, independent of the detailed dynamical assumptions on the decays of ρ, ω, and [Formula: see text]. We also wish to point out that an upper bound for the ρ–ω mixing strength in the 2π decay mode can be obtained from the knowledge of the masses and partial decay rates of channels other than 2π of ρ and ω.

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Antiferromagnetic transitions of Dirac fermions in three dimensions

Physical Review B ◽

10.1103/physrevb.102.155152 ◽

2020 ◽

Vol 102 (15) ◽

Cited By ~ 1

Author(s):

Yiqun Huang ◽

Huaiming Guo ◽

Joseph Maciejko ◽

Richard T. Scalettar ◽

Shiping Feng

Keyword(s):

Three Dimensions ◽

Dirac Fermions ◽

Antiferromagnetic Transitions

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Maximum force and naked singularities in higher dimensions

International Journal of Modern Physics D ◽

10.1142/s0218271820430087 ◽

2020 ◽

Vol 29 (14) ◽

pp. 2043008

Author(s):

John D. Barrow

Keyword(s):

General Relativity ◽

Higher Dimensions ◽

Three Dimensions ◽

Maximum Force ◽

Naked Singularities ◽

Gravitational Forces ◽

New Perspective ◽

The Masses

We discuss the existence of maximum forces in ([Formula: see text])-dimensional spacetimes and show that the existence of a mass-independent maximum force does not occur in general relativity in spaces of more than three dimensions. Instead, the maximum force increases with the masses of merging objects as [Formula: see text] and allows unbounded gravitational forces to occur. This suggests that naked singularities can arise in more than three dimensions because they are unprotected by a maximum force at the horizon surface. This creates a new perspective on the expectation of naked singularities in higher dimensions.

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Topological insulators and the Kane–Mele invariant: Obstruction and localization theory

Reviews in Mathematical Physics ◽

10.1142/s0129055x20500178 ◽

2019 ◽

Vol 32 (06) ◽

pp. 2050017

Author(s):

Severin Bunk ◽

Richard J. Szabo

Keyword(s):

Time Reversal ◽

Quantum Systems ◽

Three Dimensions ◽

Periodic Lattice ◽

Geometric Constructions ◽

Lattice Systems ◽

Localization Theory ◽

De Rham ◽

Pfaffian Formula ◽

Bundle Gerbes

We present homotopy theoretic and geometric interpretations of the Kane–Mele invariant for gapped fermionic quantum systems in three dimensions with time-reversal symmetry. We show that the invariant is related to a certain 4-equivalence which lends it an interpretation as an obstruction to a block decomposition of the sewing matrix up to non-equivariant homotopy. We prove a Mayer–Vietoris Theorem for manifolds with [Formula: see text]-actions which intertwines Real and [Formula: see text]-equivariant de Rham cohomology groups, and apply it to derive a new localization formula for the Kane–Mele invariant. This provides a unified cohomological explanation for the equivalence between the discrete Pfaffian formula and the known local geometric computations of the index for periodic lattice systems. We build on the relation between the Kane–Mele invariant and the theory of bundle gerbes with [Formula: see text]-actions to obtain geometric refinements of this obstruction and localization technique. In the preliminary part we review the Freed–Moore theory of band insulators on Galilean spacetimes with emphasis on geometric constructions, and present a bottom-up approach to time-reversal symmetric topological phases.

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