Paper introduces a new indicator to predict financial extremes using stock price network degree.
problem Predicting financial market extremes during bull and bear markets.
method Constructs an indicator based on the degree of stock price network generated from time series.
result The new indicator shows strong predictive power for financial extremes, both peaks and troughs.
New math shows many 3D hyperbolic shapes can fit together.
problem Counting specific 3D shapes that fit together.
method Examined both arithmetic and non-arithmetic shapes, focusing on their volume.
result The number of such shapes grows super-exponentially with volume.
The paper proves many hyperbolic manifolds have similar growth rates to all hyperbolic manifolds.
problem Understanding growth rates of hyperbolic manifolds.
method Proving existence of many compact hyperbolic manifolds as boundaries of other hyperbolic manifolds.
result Establishes that compact hyperbolic arithmetic n-manifolds have the same growth rate as all hyperbolic n-manifolds.
We introduce a model of super-exponential financial bubbles with two assets (risky and risk-free), in which rational investors and noise traders co-exist. Rational investors form expectations on the return and risk of a risky asset and maximize their constant relative risk aversion expected utility with respect to thei…
We present a novel analysis extending the recent work of Mizuno et al. [2002] on the hyperinflations of Germany (1920/1/1-1923/11/1), Hungary (1945/4/30-1946/7/15), Brazil (1969-1994), Israel (1969-1985), Nicaragua (1969-1991), Peru (1969-1990) and Bolivia (1969-1985). On the basis of a generalization of Cagan's model …
Using a recently introduced rational expectation model of bubbles, based on the interplay between stochasticity and positive feedbacks of prices on returns and volatility, we develop a new methodology to test how this model classifies 9 time series that have been previously considered as bubbles ending in crashes. The …
TDA detects financial bubbles through early warning signals.
problem Detecting financial bubbles early.
method Using Log-Periodic Power Law Singularity (LPPLS) model to fit financial time series data.
result TDA generates early warning signals when LPPLS model fits the data.
Proves convergence of mean curvature flow on cylinders with unique continuation.
problem Understanding the convergence and uniqueness of mean curvature flow on cylindrical surfaces.
method Proves convergence and provides unique continuation results for mean curvature flow on cylinders.
result Proves that rescaled mean curvature flow on cylinders converging super-exponentially must coincide with the cylinder itself.
New method uses hyperbolic space for faster phylogenetic tree inference.
problem Inefficient Euclidean-based phylogenetic inference in high dimensions.
method Developed novel hyperbolic extensions of sequential search algorithms and variational inference methods.
result Improved speed, scalability and performance in phylogenetic inference.
We construct 2-dimensional CAT(-1) groups which contain free subgroups with arbitrary iterated exponential distortion, and with distortion higher than any iterated exponential.
We produce examples of groups of type F_3 with 2-dimensional Dehn functions of the form exp^n(x) (a tower of exponentials of height n), where n is any natural number.
New flag-no-square 4-manifolds discovered with unique triangulations.
problem Identifying 4-manifolds with specific triangulation properties.
method Introduced star-connected-sum operation to preserve flag-no-square property; derived new constructions.
result Found non-aspherical flag-no-square 4-manifolds, answering a question by Przytycki and Swiatkowski.
For spherically symmetric distributions, efficient quantisation can be achieved with moderate sample sizes.
problem Optimal quantisation in high dimensions requires large sample sizes, making it impractical.
method Uniformly distributed random quantisers on a sphere of suitable radius achieve exceptional performance.
result For moderate sample sizes, quantisation error can be efficiently computed and approximated.
Let G be an arithmetic Kleinian group, and let O be the associated hyperbolic 3-orbifold or 3-manifold. In this paper, we prove that, in many cases, G is large, which means that some finite index subgroup admits a surjective homomorphism onto a non-abelian free group. This has many consequences, including that O has in…
Model predicts Bitcoin bubbles with network properties and LPPLS model.
problem Predicting Bitcoin bubbles and crashes using network properties and LPPLS model.
method Generalized Metcalfe's law and LPPLS model.
result Bubbles are detected with a universal super-exponential unsustainable growth pattern.
Improved lower bound for pseudo-Anosov maps on surfaces.
problem Finding a more efficient lower bound for pseudo-Anosov maps.
method Proved a polynomial dependence on genus and punctures.
result Improved the dependence from super-exponential to polynomial.
Episodes of market crashes have fascinated economists for centuries. Although many academics, practitioners and policy makers have studied questions related to collapsing asset price bubbles, there is little consensus yet about their causes and effects. This review and essay evaluates some of the hypotheses offered to …
VISTA learns causal structures by integrating local subgraphs, improving accuracy and efficiency.
problem Efficiently learning causal structures from high-dimensional observational data.
method VISTA decomposes the global causal structure learning problem into local subgraphs based on Markov Blankets, integrating them via a weighted voting mechanism.
result VISTA achieves notable improvements in accuracy and efficiency over existing methods.
Our analysis of financial data, in terms of super-exponential growth, suggests that the seed of the 2002/03 crisis of the Dutch supermarket giant AHOLD was planted in 1996. It became quite visible in 1999 when the post-bubble destabilization regime was well-developed and acted as the precursor of an inevitable collapse…
Cryptocurrency market analysis reveals stable properties despite continuous emergence and disappearance of new coins.
problem Lack of comprehensive analysis of the entire cryptocurrency market.
method Analysis of 1,469 cryptocurrencies introduced between April 2013 and June 2017 using ecological modeling.
result Neutral model of evolution can reproduce key empirical observations of the cryptocurrency market.
We analyze a controlled price formation experiment in the laboratory that shows evidence for bubbles. We calibrate two models that demonstrate with high statistical significance that these laboratory bubbles have a tendency to grow faster than exponential due to positive feedback. We show that the positive feedback ope…
Imitative and contrarian behaviors are the two typical opposite attitudes of investors in stock markets. We introduce a simple model to investigate their interplay in a stock market where agents can take only two states, bullish or bearish. Each bullish (bearish) agent polls m "friends'' and changes her opinion to bear…
Optimal experiments tighten causal effect bounds efficiently.
problem Selecting experiments to tighten causal effect bounds from observational data.
method Formalized as max-potency problem, NP-hard. Polynomial-programming framework with graphical pruning criteria.
result Pruning criteria reduce search space significantly, enabling efficient experiment selection.
Let (X,g) be a metrically complete, simply connected Riemannian manifold with bounded geometry and pinched negative curvature, i.e. there are constants a>b>0 such that -a^2<K<-b^2 for all sectional curvatures K. Here bounded geometry is used in the sense that all covariant derivatives of the Riemannian curvature tensor…
Study detects Chinese stock market bubbles using LPPLS confidence indicator.
problem Early detection of stock market bubbles in China.
method LPPLS confidence indicator applied to CSI 300 index data.
result LPPLS detects positive and negative bubbles with high accuracy.
This paper addresses the general problem of modelling and learning rank data with ties. We propose a probabilistic generative model, that models the process as permutations over partitions. This results in super-exponential combinatorial state space with unknown numbers of partitions and unknown ordering among them. We…
New technique shows any group can be a map's automorphism.
problem Finding maps with any given automorphism group.
method Universal technique for showing any finite automorphism group is possible.
result Any finite automorphism group can be realized by many non-isomorphic maps.
Trained neural networks perform Bayesian reasoning for tasks beyond their initial scope.
problem Performing Bayesian reasoning for tasks outside the trained neural networks' initial scope.
method Used deep generative models as priors and classification/regression networks as constraints. Approximated Bayesian inference through variational or sampling techniques.
result The approach built on top of already trained networks, expanding the addressable questions.
Unified Growth Theory contradicted by USSR economic data.
problem Unified Growth Theory fails to explain USSR economic growth.
method Analysis of historical USSR economic data.
result USSR economic growth was hyperbolic, not stagnant.
Using a family of modified Weibull distributions, encompassing both sub-exponentials and super-exponentials, to parameterize the marginal distributions of asset returns and their multivariate generalizations with Gaussian copulas, we offer exact formulas for the tails of the distribution P(S) of returns S of a port…
Abstract Coxeter groups have growth rates that are Perron numbers.
problem Understanding growth rates of Coxeter groups.
method Defined a class of Coxeter groups, ∞--spanned, and analyzed their growth rates. result For ∞--spanned Coxeter groups, geodesic growth rate strictly dominates word growth rate and appears to be a Perron number. Keeping a basic tenet of economic theory, rational expectations, we model the nonlinear positive feedback between agents in the stock market as an interplay between nonlinearity and multiplicative noise. The derived hyperbolic stochastic finite-time singularity formula transforms a Gaussian white noise into a rich time…
Linear GDP growth explained by AI performance models.
problem Missing explanation for linear GDP growth since 1950.
method Compare AI performance models to GDP growth patterns.
result Linear growth in AI performance may explain GDP growth.
World GDP growth is predicted to become unsustainable.
problem Predicting the future of world economic growth.
method Analysis of World Bank data on GDP growth rates.
result World economic growth is predicted to become unsustainable.
Unified Growth Theory contradicted by Asian economic data.
problem Unified Growth Theory fails to explain Asian economic growth.
method Analysis of historical economic growth data in Asia.
result Asian economic growth was hyperbolic, not stagnant.
Unified Growth Theory contradicted by African economic data.
problem Contradiction between Unified Growth Theory and African economic growth data.
method Analysis of Galor's data for African countries.
result Data contradicts Unified Growth Theory's claims about economic growth regimes.
Graphs indistinguishable by GNNs are fully characterized.
problem Limited expressiveness of GNNs in distinguishing non-isomorphic graphs.
method Theory of covering spaces to characterize GNN equivalence classes.
result Arbitrarily many non-isomorphic graphs that GNNs cannot distinguish.
Unified Growth Theory contradicted by Latin American economic data.
problem Unified Growth Theory fails to explain Latin American economic growth.
method Analysis of historical economic growth data from Maddison.
result Unified Growth Theory is inconsistent with Latin American data.
Analyzes historical economic growth trends using hyperbolic distributions.
problem Understanding the natural tendency of historical economic growth.
method Data analysis of world and regional economic growth using hyperbolic distributions.
result Historical economic growth follows hyperbolic distributions with specific parameters.
Study measures economic growth sources in Iran's mining sector using neoclassical growth accounting.
problem Determining the share of economic growth sources in Iran's mining sector.
method Neoclassical growth accounting approach, using production function and Solow residual equation.
result Average annual growth rate of TFP was 2.94% over 30 years.
Simple math predicts growth trends.
problem Complex growth projections are hard to understand.
method Direct or indirect analysis of growth rates.
result Simple assumptions lead to understandable growth predictions.
Unified Growth Theory debunked: economic growth is insecure and unsustainable.
problem The mystery of the great divergence in income per capita.
method Analysis of economic data to show that growth trajectories are increasing vertically over time.
result Unified Growth Theory is incorrect and promotes misleading concepts.
Calculates the systolic growth of nilpotent Lie groups, providing new insights.
problem Understanding the growth of systolic volume in nilpotent Lie groups.
method Expressed systolic growth in terms of discrete subrings, developed methods for lower bounds.
result First computations of systolic growth for non-equivalent volume growth cases.
The Unified Growth Theory is a puzzling collection of myths based on illusions created by hyperbolic distributions. Some of these myths are discussed. The examination of data shows that the three stages of growth (Malthusian Regime, Post-Malthusian Regime and Modern Growth Regime) did not exist and that Industrial Revo…
Study confined subgroups in groups with contracting elements, showing their growth rate is strictly greater than half of the ambient growth rate.
problem Understanding the growth rate of confined subgroups in groups with contracting elements.
method Through boundary actions, analyzing the Hopf decomposition and quotient growth.
result Confined subgroups have a growth rate strictly greater than half of the ambient growth rate.
New method finds large counterexamples by selectively exploring triangulations.
problem Finding small counterexamples in 3-manifold triangulations. method Selective enumeration of triangulations using heuristics.
result Found counterexamples to three conjectures about vertex triangulations.
The US GDP per capita growth alternates between high and low rates, with an average growth rate of 1.6% since 1800.
problem Understanding the fluctuations and stability of US GDP growth rates over time.
method Wavelet transform analysis of US GDP per capita data from 1800 to 2010.
result The growth rate of US GDP per capita is bimodal, alternating between high and low rates with an average of 1.6% since 1800.
Growth rates of geodesics on modular orbifolds are studied.
problem Understanding growth rates of geodesics on modular orbifolds.
method Exhaustion of modular orbifold by compact subsurfaces, analysis of low lying geodesics and reciprocal geodesics.
result Growth rates of low lying geodesics and reciprocal geodesics converge to the full set's growth rate.