2,523 research outputs found
Complementarity of the Maldacena and Karch-Randall Pictures
We perform a one-loop test of the holographic interpretation of the
Karch-Randall model, whereby a massive graviton appears on an AdS_4 brane in an
AdS_5 bulk. Within the AdS/CFT framework, we examine the quantum corrections to
the graviton propagator on the brane, and demonstrate that they induce a
graviton mass in exact agreement with the Karch-Randall result. Interestingly
enough, at one loop order, the spin 0, spin 1/2 and spin 1 loops contribute to
the dynamically generated (mass)^2 in the same 1: 3: 12 ratio as enters the
Weyl anomaly and the 1/r^3 corrections to the Newtonian gravitational
potential.Comment: 20 pages, Revtex 3, Discussion on the absence of a scalar ghost
clarified; Additional details on the computation give
Frontispiece: A Pd-Catalyzed Synthesis of Functionalized Piperidines
Pd Catalysis A readily available cyclic carbamate functions as a general precursor to a range of functionalized piperidine products using a new Pd-catalyzed annulation strategy. An asymmetric catalytic variant provides a rapid and efficient means to access these heterocycles with high to excellent levels of enantiocontrol. In addition, these richly functionalized compounds are amenable to further chemoselective elaboration. For more information, see the Communication by J.â
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President trump tweets supreme leader Kim Jong-Un on nuclear weapons
A set of 125 tweets about North Korea's Supreme Leader Kim Jong-Un by President Trump from 2013 to 2018 are analysed by means of the data mining technique, sentiment analysis. The intention is to explore the contents and sentiments of the messages contained, the degree to which they differ, and their implications about President Trump's understanding and approach to international diplomacy. The results suggest a predominantly positive emotion in relation to tweets about North Korea, despite the use of questionable nicknames such as "Little Rocket Man". A comparison is made between the tweets on North Korea and climate change, madefrom 2011-2015, as Trump has tweeted many times on both issues. It is interesting to find that Trump's tweets on North Korea have significantly higher positive polarity scores than his tweets on climate change
Do we need stochastic volatility and generalised autoregressive conditional heteroscedasticity? Comparing squared end-of-day returns on FTSE
The paper examines the relative performance of Stochastic Volatility (SV) and Generalised Autoregressive Conditional Heteroscedasticity (GARCH) (1,1) models fitted to ten years of daily data for FTSE. As a benchmark, we used the realized volatility (RV) of FTSE sampled at 5 min intervals taken from the Oxford Man Realised Library. Both models demonstrated comparable performance and were correlated to a similar extent with RV estimates when measured by ordinary least squares (OLS). However, a crude variant of Corsiâs (2009) Heterogeneous Autoregressive (HAR) model, applied to squared demeaned daily returns on FTSE, appeared to predict the daily RV of FTSE better than either of the two models. Quantile regressions suggest that all three methods capture tail behaviour similarly and adequately. This leads to the question of whether we need either of the two standard volatility models if the simple expedient of using lagged squared demeaned daily returns provides a better RV predictor, at least in the context of the sample
Risk Measurement and Risk Modelling using Applications of Vine Copulas
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This paper features an application of Regular Vine copulas which are a novel and recently developed statistical and mathematical tool which can be applied in the assessment of composite nancial risk. Copula-based dependence modelling is a popular tool in nancial applications, but is usuall
An entropy based analysis of the relationship between the DOW JONES Index and the TRNA Sentiment series
This paper features an analysis of the relationship between the DOW JONES Industrial Average Index (DJIA) and a sentiment news series using daily data obtained from the Thomson Reuters News Analytics (TRNA)1 provided by SIRCA (The Securities Industry Research Centre of the Asia Pacic). The recent growth in the availability of on-line financial news sources such as internet news and social media sources provides instantaneous access to financial news. Various commercial agencies have started developing their own filtered financial news feeds which are used by investors and traders to support their algorithmic trading strategies. Thomson Reuters News Analytics (TRNA)2 is one such data set. In this study we use the TRNA data set to construct a series of daily sentiment scores for Dow Jones Industrial Average (DJIA) stock index componen
Volatility Spillovers from the Chinese Stock Market to Economic Neighbours
This paper examines whether there is evidence of spillovers of volatility from the Chinese stock
market to its neighbours and trading partners, including Australia, Hong Kong, Singapore, Japan
and USA. Chinaâs increasing integration into the global market may have important consequences
for investors in related markets. In order to capture these potential effects, we explore these issues
using an Autoregressive Moving Average (ARMA) return equation. A univariate GARCH model
is then adopted to test for the persistence of volatility in stock market returns, as represented by
stock market indices. Finally, univariate GARCH, multivariate VARMA-GARCH, and multivariate
VARMA-AGARCH models are used to test for constant conditional correlations and volatility
spillover effects across these markets. Each model is used to calculate the conditional volatility
between both the Shenzhen and Shanghai Chinese markets and several other markets around the
Pacific Basin Area, including Australia, Hong Kong, Japan, Taiwan and Singapore, during four
distinct periods, beginning 27 August 1991 and ending 17 November 2010. The empirical results
show some evidence of volatility spillovers across these markets in the pre-GFC periods, but there is
little evidence of spillover effects from China to relat
Fake News and Indifference to Truth
State of the Union Addresses (SOUA) by two recent US Presidents, President
Obama (2016) and President Trump (2018), and a series of recent of tweets by
President Trump, are analysed by means of the data mining technique, sentiment
analysis. The intention is to explore the contents and sentiments of the
messages contained, the degree to which they dier, and their potential implications
for the national mood and state of the economy. President Trump's 2018
SOUA and his sample tweets are identied as being more positive in sentiment
than President Obama's 2016 SOUA. This is conrmed by bootstrapped t tests
and non-parametric sign tests on components of the respective sentiment scores.
The issue of whether overly positive pronouncements amount to self-promotion,
rather than intrinsic merit or sentiment, is a topic for future research
Recent Developments in Financial Economics and Econometrics: An Overview
Research papers in empirical finance and financial econometrics are among the most widely cited, downloaded and viewed articles in the discipline of Finance. The special issue presents several papers by leading scholars in the field on âRecent Developments in Financial Economics and Econometricsâ. The breadth of coverage is substantial, and includes original research and comprehensive review papers on theoretical, empirical and numerical topics in Financial Economics and Econometrics by leading researchers in finance, financial economics, financial econometrics and financial statistics. The purpose of this special issue on âRecent Developments in Financial Economics and Econometricsâ is to highlight several novel and significant developments in financial economics and financial econometrics, specifically dynamic price integration in the global gold market, a conditional single index model with local covariates for detecting and evaluating active management, whether the Basel Accord has improved risk management during the global financial crisis, the role of banking regulation in an economy under credit risk and liquidity shock, separating information maximum likelihood estimation of the integrated volatility and covariance with micro-market noise, stress testing correlation matrices for risk management, whether bank relationship matters for corporate risk taking, with evidence from listed firms in Taiwan, pricing options on stocks denominated in different currencies, with theory and illustrations, EVT and tail-risk modelling, with evidence from market indices and volatility series, the economics of data using simple model free volatility in a high frequency world, arbitrage-free implied volatility surfaces for options on single stock futures, the non-uniform pricing effect of employee stock options using quantile regression, nonlinear dynamics and recurrence plots for detecting financial crisis, how news sentiment impacts asset volatility, with evidence from long memory and regime-switching approaches, quantitative evaluation of contingent capital and its applications, high quantiles estimation with Quasi-PORT and DPOT, with an application to value-at-risk for financial variables, evaluating inflation targeting based on the distribution of inflation and inflation volatility, the size effects of volatility spillovers for firm performance and exchange rates in tourism, forecasting volatility with the realized range in the presence of noise and non-trading, using CARRX models to study factors affecting the volatilities of Asian equity markets, deciphering the Libor and Euribor spreads during the subprime crisis, information transmission between sovereign debt CDS and other financial factors for Latin America, time-varying mixture GARCH models and asymmetric volatility, and diagnostic checking for non-stationary ARMA models with an application to financial data
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