scholarly journals Higher-spin symmetry vs. boundary locality, and a rehabilitation of dS/CFT

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Adrian David ◽  
Yasha Neiman
Keyword(s):  
Partition Function ◽  
First Principles ◽  
Spin Symmetry ◽  
Feynman Diagrams ◽  
Vector Model ◽  
Precise Form ◽  
Higher Spin ◽  
Shell Boundary ◽  
First Time ◽  
Do So

Abstract We consider the holographic duality between 4d type-A higher-spin gravity and a 3d free vector model. It is known that the Feynman diagrams for boundary correlators can be encapsulated in an HS-algebraic twistorial expression. This expression can be evaluated not just on separate boundary insertions, but on entire finite source distributions. We do so for the first time, and find that the result ZHS disagrees with the usual CFT partition function. While such disagreement was expected due to contact corrections, it persists even in their absence. We ascribe it to a confusion between on-shell and off-shell boundary calculations. In Lorentzian boundary signature, this manifests via wrong relative signs for Feynman diagrams with different permutations of the source points. In Euclidean, the signs are instead ambiguous, spoiling would-be linear superpositions. Framing the situation as a conflict between boundary locality and HS symmetry, we sacrifice locality and choose to take ZHS seriously. We are rewarded by the dissolution of a long-standing pathology in higher-spin dS/CFT. Though we lose the connection to the local CFT, the precise form of ZHS can be recovered from first principles, by demanding a spin-local boundary action.

In the Labyrinth

2017 ◽  
Author(s):  
Andrew McNeillie
Keyword(s):  
The Right ◽  
First Time ◽  
Do So

It is now widely acknowledged, and far beyond Ireland, that Tim Robinson’s two volumes jointly known as Stones of Aran (‘Pilgrimage’ and ‘Labyrinth’) are modern classics, exemplary in every way of how to write about place and to do so with a formal, literary accomplishment that more than earns the right to nod at Ruskin’s own classic. In 2012, Robinson went back to Árainn, the largest of the three islands, for the first time in nearly ten years. He did so at the urging of Andrew McNeillie, with whom he spent two and a half days revisiting old haunts. This chapter makes account of the occasion and uses, in the process, a unique document provided by Robinson as an experiment in annotating his work. This prompts McNeillie to investigate some of his own annotations and footnotes to Aran.

Reconstituting the International, 1918–1923

2017 ◽  
Author(s):  
Talbot C. Imlay
Keyword(s):  
Seismic Events ◽  
Great War ◽  
Bolshevik Revolution ◽  
Meaning And Purpose ◽  
Post War ◽  
The Impact ◽  
First Time ◽  
The Great War ◽  
Do So ◽  
Lengthy Process

This chapter examines the post-war efforts of European socialists to reconstitute the Socialist International. Initial efforts to cooperate culminated in an international socialist conference in Berne in February 1919 at which socialists from the two wartime camps met for the first time. In the end, however, it would take four years to reconstitute the International with the creation of the Labour and Socialist International (LSI) in 1923. That it took so long to do so is a testimony to the impact of the Great War and to the Bolshevik revolution. Together, these two seismic events compelled socialists to reconsider the meaning and purpose of socialism. The search for answers sparked prolonged debates between and within the major parties, profoundly reconfiguring the pre-war world of European socialism. One prominent stake in this lengthy process, moreover, was the nature of socialist internationalism—both its content and its functioning.

scholarly journals Breast Cancer Cell Re-Dissemination from Lung Metastases—A Mechanism for Enhancing Metastatic Burden

2021 ◽  
Vol 10 (11) ◽  
pp. 2340
Author(s):  
Lucia Borriello ◽  
John Condeelis ◽  
David Entenberg ◽  
Maja H. Oktay
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Metastatic Disease ◽  
Breast Cancer Cells ◽  
Lung Metastases ◽  
Primary Tumors ◽  
Metastatic Burden ◽  
First Time ◽  
Do So

Although metastatic disease is the primary cause of mortality in cancer patients, the mechanisms leading to overwhelming metastatic burden are still incompletely understood. Metastases are the endpoint of a series of multi-step events involving cancer cell intravasation, dissemination to distant organs, and outgrowth to metastatic colonies. Here we show, for the first-time, that breast cancer cells do not solely disseminate to distant organs from primary tumors and metastatic nodules in the lymph nodes, but also do so from lung metastases. Thus, our findings indicate that metastatic dissemination could continue even after the removal of the primary tumor. Provided that the re-disseminated cancer cells initiate growth upon arrival to distant sites, cancer cell re-dissemination from metastatic foci could be one of the crucial mechanisms leading to overt metastases and patient demise. Therefore, the development of new therapeutic strategies to block cancer cell re-dissemination would be crucial to improving survival of patients with metastatic disease.

scholarly journals The origins of charge separation in anisotropic facet photocatalysts investigated through first-principles calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18500-18508
Author(s):  
Shun-Chiao Chan ◽  
Yu-Lin Cheng ◽  
Bor Kae Chang ◽  
Che-Wun Hong
Keyword(s):  
First Principles ◽  
Charge Separation ◽  
First Principles Calculations ◽  
Design And Development ◽  
First Time

The anisotropic (110)/(100) facet junction built-in potential in SrTiO3 is estimated at 2.9 V using DFT for the first time, which can help in further design and development of efficient photocatalysts using such anisotropic-facet engineering.

scholarly journals Bulk interactions and boundary dual of higher-spin-charged particles

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Adrian David ◽  
Yasha Neiman
Keyword(s):  
Relative Velocity ◽  
Black Hole Solution ◽  
Vector Model ◽  
Boundary Theory ◽  
Gauge Fields ◽  
Leading Order ◽  
Gravitational Forces ◽  
Penrose Transform ◽  
Higher Spin ◽  
Non Locality

Abstract We consider higher-spin gravity in (Euclidean) AdS4, dual to a free vector model on the 3d boundary. In the bulk theory, we study the linearized version of the Didenko-Vasiliev black hole solution: a particle that couples to the gauge fields of all spins through a BPS-like pattern of charges. We study the interaction between two such particles at leading order. The sum over spins cancels the UV divergences that occur when the two particles are brought close together, for (almost) any value of the relative velocity. This is a higher-spin enhancement of supergravity’s famous feature, the cancellation of the electric and gravitational forces between two BPS particles at rest. In the holographic context, we point out that these “Didenko-Vasiliev particles” are just the bulk duals of bilocal operators in the boundary theory. For this identification, we use the Penrose transform between bulk fields and twistor functions, together with its holographic dual that relates twistor functions to boundary sources. In the resulting picture, the interaction between two Didenko-Vasiliev particles is just a geodesic Witten diagram that calculates the correlator of two boundary bilocals. We speculate on implications for a possible reformulation of the bulk theory, and for its non-locality issues.

Some Palaeoliths from South Arabia

1954 ◽  
Vol 19 (2) ◽  
pp. 189-218 ◽  
Author(s):  
G. Caton-Thompson
Keyword(s):  
Geographical Society ◽  
South Arabia ◽  
First Time ◽  
Do So

The material here described was found in the Hadhramaut by Elinor Gardner and myself between November 1937 and March 1938. My personal investigation of the Palaeolithic Age was limited by pre-Islamic excavations, and I am therefore indebted to her for the gathering of most of the specimens in situ in terrace gravels, and to her detailed study of their positions.The collection consists mainly of groups from four fairly widely separated localities; the physiography of these has already been outlined in a comprehensive paper published in the Geographical Journal. Whenever appropriate to the purpose of this account, which is to place for the first time on illustrated record all we observed about the palaeoliths, I have reused in this different context illustrations of Quaternary environment which appeared in that Journal. With thanks I acknowledge the permission of the Royal Geographical Society to do so.

First-principles study of electronic structure, chemical bonding and elastic properties for new superconductor CaFeAs2

2017 ◽  
Vol 31 (02) ◽  
pp. 1650263
Author(s):  
J. G. Yan ◽  
Z. J. Chen ◽  
G. B. Xu ◽  
Z. Kuang ◽  
T. H. Chen ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Elastic Properties ◽  
Density Of States ◽  
First Principles ◽  
Elastic Anisotropy ◽  
First Principles Calculation ◽  
Hard Material ◽  
Dirac Cone ◽  
First Time ◽  
New Superconductor

Using first-principles calculation we investigated the structural, electronic and elastic properties of paramagnetic CaFeAs2. Our results indicated that the density of states (DOS) was dominated predominantly by Fe-3[Formula: see text] states at Fermi levels, and stronger hybridization exists between As1 and As1 atoms. Three hole pockets are formed at [Formula: see text] and Z points, and two electronic pockets are formed at A and E points. The Dirac cone-like bands appear near B and D points. For the first time we calculated the elastic properties and found that CaFeAs2 is a mechanically stable and moderately hard material, it has elastic anisotropy and brittleness, which agrees well with the bonding picture and the calculation of Debye temperature ([Formula: see text]).

Magnetic thermodynamics of fcc Ni from first-principles partition function approach

2010 ◽  
Vol 108 (12) ◽  
pp. 123514 ◽  
Author(s):  
Shun-Li Shang ◽  
James E. Saal ◽  
Zhi-Gang Mei ◽  
Yi Wang ◽  
Zi-Kui Liu
Keyword(s):  
Partition Function ◽  
First Principles ◽  
Function Approach

Efficient Modulation of Catalytic Performance of Electrocatalytic Nitrogen Reduction with Transition Metal Anchored N/O-codoped Graphene by Coordination Engineering

2021 ◽  
Author(s):  
Xiaolin Wang ◽  
Li-Ming Yang
Keyword(s):  
Nitrogen Fixation ◽  
Transition Metal ◽  
High Throughput ◽  
First Principles ◽  
High Throughput Screening ◽  
Catalytic Performance ◽  
Nitrogen Reduction ◽  
Highly Efficient ◽  
First Time

We for the first time report the discovery of a series of highly efficient electrocatalysts, i.e., transition metal anchored N/O-codoped graphene, for nitrogen fixation via high-throughput screening combined with first-principles...

Thermodynamic Properties of CaSiO3 Perovskite at High Pressure and High Temperature

2009 ◽  
Vol 64 (5-6) ◽  
pp. 399-404 ◽  
Author(s):  
Zi-Jiang Liu ◽  
Xiao-Ming Tan ◽  
Yuan Guo ◽  
Xiao-Ping Zheng ◽  
Wen-Zhao Wu
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
High Pressures ◽  
Local Density ◽  
Harmonic Approximation ◽  
Debye Model ◽  
Functional Theory ◽  
Casio3 Perovskite ◽  
First Time

The thermodynamic properties of tetragonal CaSiO3 perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines the ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state is in excellent agreement with the observed values at ambient condition. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

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