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Aug 1, 2026·arXiv (Cornell University)
0 cites
On the Log Determinant of Sample Correlation Matrices under Gaussianity

Hongru Zhao

We prove a central limit theorem for the log determinant of a Gaussian Pearson sample correlation matrix as the dimension diverges. Only two conditions are imposed: the population correlation matrix is positive definite, and the sample degrees of freedom are at least the dimension. Both are necessary for the ordinary log determinant to be finite. To the best of our knowledge, no previous central limit theorem covers this full nonsingular domain. It covers every aspect ratio from dilute growth to the square hard edge. No uniform lower or upper bound is imposed on the eigenvalues of the population correlation matrices: the smallest may approach zero and the largest may diverge. The proof develops a coordinatewise Wiener chaos reduction for the random diagonal normalization and combines it with an exact Wishart transform comparison. Geometrically, the statistic is twice the log volume of a random parallelotope spanned by standardized Gaussian coordinate vectors.

Open access
2 source records
Random Matrices and Applications
Statistical Mechanics and Entropy
Markov Chains and Monte Carlo Methods
Original source
Jul 6, 2026·Zenodo (CERN European Organization for Nuclear Research)
0 cites
Proof of the Birch–Swinnerton–Dyer Conjecture via Euler Product Linearization and Self-Adjoint Operator Spectral Theory: Version 2.0

Jie Yang

We prove the full Birch–Swinnerton–Dyer conjecture for all elliptic curves over Q. Using a fundamentally new approach that extends the method developed for the Riemann Hypothesis, we construct a sequence of finite-dimensional self-adjoint matrices from the Euler product of the elliptic curve L-function. We establish a strict spectral correspondence between the eigenvalues of these matrices and the squares of the distances from the critical point s=1 to the zeros of L (E, s), with no prior knowledge of zero locations required in the construction. Using mathematical induction, perturbation bounds and the monotone convergence theorem for self-adjoint operators, we extend these results to the infinite-dimensional case, proving that the order of vanishing of L (E, s) at s=1 equals the rank of the Mordell–Weil group E (Q). We then prove the exact leading-term formula relating the first non-vanishing coefficient of the Taylor expansion of L (E, s) at s=1 to the arithmetic invariants of the elliptic curve, including the period, regulator, Tamagawa numbers, and the order of the Tate–Shafarevich group, which we prove is finite. We also embed this result into the broader universal self-adjoint integral operator framework. Keywords: Birch–Swinnerton–Dyer conjecture; elliptic curve; L-function; self-adjoint operator; spectral correspondence; Mordell–Weil rank; Tate-Shafarevich group MSC 2020 Classification: 11G05; 11M41; 47A10; 14H52; 11G40

Open access
2 source records
Spectral Theory in Mathematical Physics
Holomorphic and Operator Theory
Random Matrices and Applications
Original source
May 13, 2026·Zenodo (CERN European Organization for Nuclear Research)
1 cites
High-Precision Approximation of Riemann Zeros via the Truncated Weil Form

Akiva Groskin

The Connes–van Suijlekom truncated Weil quadratic form, indexed by a cutoff parameter c that controls the primes p ≀ c entering the operator, produces a ground state whose Fourier–Mellin zeros provably lie on the critical line; whether they converge to the Riemann zeros as c → ∞ is open (Connes 2026; Connes–Consani–Moscovici 2025). We present, to our knowledge, the first independent public implementation of the Connes–van Suijlekom Galerkin matrix at sixteen cutoffs (c = 13 through 67, plus c = 100). Across the in-sample window c = 13 through c = 67 at N = 100, the first-zero absolute error |Îł1 − Îł1Riemann| shrinks monotonically from ∌2×10−55 to ∌1.5×10−168, a 113-OOM convergence across fifteen cutoffs. The smallest-positive even-sector eigenvalue λmineven separately reaches ∌10−334 at c = 100, N = 250 (275-OOM span from c = 13). Out-of-sample test at c = 100. On the four-point N-sweep N ∈ {100, 150, 200, 250} at dps = 500, consecutive first-difference ratios 0.837 and 0.836 match to two decimal places. Aitken-Δ2 on the two overlapping triples yields log10|λ∞even| ≈ −536.8 and ≈ −533.7, approaching the Connes 2026 §6.4 heuristic prediction (≈ −530.4) monotonically with N (6.4 and 3.3 OOM gaps out of |x∞| ∌ 530). The same eigenvector recovers Îł1, 
, Îł10 to 307–329 matching digits at N = 250, dps = 500. Under the unitary equivalence with Connes–Consani–Moscovici Lemma 5.1, this is the deepest such Galerkin-truncation recovery in the public Connes–van Suijlekom / Connes–Consani–Moscovici literature, subject to a hypothesis-status caveat. The raw finite-N matrix carries a small block of negative-sign eigenvalues at the finite archimedean cutoff T = 800; these are an artifact of that cutoff and are absent once T is increased, so the smallest-positive even-sector eigenvalue is the genuine smallest one (continuum positivity of QWλ is RH-equivalent and is not assumed at λ = √100). The fit |log10 λmin| ≈ 13.24 c0.634 on c ≀ 67 at N = 100 is shown to be a finite-N rate, falsified at c = 100, N = 200 by 49 OOM in the direction of faster decay. Structural observations include approximate eigenvector c-invariance (overlap ≄ 0.9498 on all 105 cutoff pairs despite eigenvalues differing by 113 OOM), multi-zero convergence universality (all ten detectable zeros within 3.8% of each other), an empirical Galerkin-convergence exponent s(c) ≈ 55 log c − 128, un-rescaled Galerkin bulk-spectrum Poisson statistics (ÎČ < 0.05; this is a structural diagnostic of the truncated operator, not a test of Montgomery's conjecture, which applies to locally-rescaled zero spacings), and tight bulk invariants log|det Qc| ≈ −65.6 c + 542 (R2 = 0.997). We make no claim of proof; the contribution is reproducible numerical data and its careful interpretation under the existing CvS / CCM framework. All code, data, and ancillary files are publicly available. Version 3.3 (2026-06-26) correction. The negative-sign eigenvalue blocks reported at c = 100 and for L(s, χ3) at c = 23, 29 are a finite archimedean-cutoff (T) artifact, not a feature of the operator: they are stable in working precision but vanish once T is increased, so cutoff-free the relevant even sectors are non-negative and the smallest-positive branch is the genuine smallest eigenvalue. No quantitative result changes. See ERRATA.md and the paper's note added in revision. The cutoff sensitivity was independently identified by B. W. A. Silva, consistent with the naturally even, positive ground state reported by R. Andrews; the investigation was prompted by A. Connes.

Open access
6 source records
Random Matrices and Applications
Spectral Theory in Mathematical Physics
Mathematical functions and polynomials
Original source
Apr 13, 2026·Zenodo (CERN European Organization for Nuclear Research)
0 cites
High-Precision Galerkin Experiments on the Connes–van Suijlekom Truncated Weil Form, with an Out-of-Sample Empirical Test at c=100

Akiva Groskin

The Connes–van Suijlekom truncated Weil quadratic form, indexed by a cutoff parameter c that controls the primes p ≀ c entering the operator, produces a ground state whose Fourier–Mellin zeros provably lie on the critical line; whether they converge to the Riemann zeros as c → ∞ is open (Connes 2026; Connes–Consani–Moscovici 2025). We present, to our knowledge, the first independent public implementation of the Connes–van Suijlekom Galerkin matrix at sixteen cutoffs (c = 13 through 67, plus c = 100). Across the in-sample window c = 13 through c = 67 at N = 100, the first-zero absolute error |Îł1 − Îł1Riemann| shrinks monotonically from ∌2×10−55 to ∌1.5×10−168 — a 113-OOM convergence across fifteen cutoffs. The smallest-positive even-sector eigenvalue λmineven separately reaches ∌10−334 at c = 100, N = 250 (275-OOM span from c = 13). Out-of-sample test at c = 100. On the four-point N-sweep N ∈ {100, 150, 200, 250} at dps = 500, consecutive first-difference ratios 0.837 and 0.836 match to two decimal places. Aitken-Δ2 on the two overlapping triples yields log10|λ∞even| ≈ −536.8 and ≈ −533.7, approaching the Connes 2026 §6.4 heuristic prediction (≈ −530.4) monotonically with N (6.4 and 3.3 OOM gaps out of |x∞| ∌ 530). The same eigenvector recovers Îł1, 
, Îł10 to 307–329 matching digits at N = 250, dps = 500. Under the unitary equivalence with Connes–Consani–Moscovici Lemma 5.1, this is the deepest such Galerkin-truncation recovery in the public Connes–van Suijlekom / Connes–Consani–Moscovici literature, subject to a hypothesis-status caveat: the raw finite-N matrix carries a small block of dps-stable negative-sign eigenvalues, so we report the smallest-positive branch (continuum positivity of QWλ is RH-equivalent and is not assumed at λ = √100). The fit |log10 λmin| ≈ 13.24 c0.634 on c ≀ 67 at N = 100 is shown to be a finite-N rate, falsified at c = 100, N = 200 by 49 OOM in the direction of faster decay. Structural observations include approximate eigenvector c-invariance (overlap ≄ 0.9498 on all 105 cutoff pairs despite eigenvalues differing by 113 OOM), multi-zero convergence universality (all ten detectable zeros within 3.8% of each other), an empirical Galerkin-convergence exponent s(c) ≈ 55 log c − 128, un-rescaled Galerkin bulk-spectrum Poisson statistics (ÎČ < 0.05; this is a structural diagnostic of the truncated operator, not a test of Montgomery's conjecture, which applies to locally-rescaled zero spacings), and tight bulk invariants log|det Qc| ≈ −65.6 c + 542 (R2 = 0.997). We make no claim of proof; the contribution is reproducible numerical data and its careful interpretation under the existing CvS / CCM framework. All code, data, and ancillary files are publicly available.

Open access
2 source records
Random Matrices and Applications
Spectral Theory in Mathematical Physics
Quantum many-body systems
Original source
Mar 22, 2026·Zenodo (CERN European Organization for Nuclear Research)
0 cites
Operator Factorization Beyond Hilbert Spaces: Banach Duality and Stable Levy Processes

Fontes, Ramiro

This deposit contains the Lean 4 formal verification companion (BanachLevyComplete.lean, 2,439 lines) for the paper "Operator Factorization Beyond Hilbert Spaces: Representability Obstructions, Leibniz Defects, and Chaos Characterizations for Stable LĂ©vy Processes" by Ramiro Fontes. The file has zero sorry declarations and zero axiom declarations. It integrates three layers: Part 1 — Poisson infrastructure: The symmetric Îł-stable LĂ©vy measure density with proved symmetry and nonnegativity. The Poisson mean identity E[Poisson(λ)] = λ and variance identity Var(Poisson(λ)) = λ, proved as theorems via a recurrence lemma and HasSum assembly. A canonical Poisson random variable constructed on (ℕ, poissonMeasure(λT)) with its distribution proved by Measure.map_id. Stable measure moment computations and the Blumenthal–Getoor dichotomy. Quadratic defect sharpness for the variance swap payoff. Part 2 — LĂ©vy–ItĂŽ framework: The ItĂŽ formula for compound Poisson processes proved as a finite telescoping sum via Finset.sum_range_sub. A compound Poisson path defined as a concrete function, proved to start at zero and to have the correct terminal value. The compensated Poisson integral constructed as an LÂČ limit of compound Poisson finite sums, with linearity inherited from finite-sum linearity and centering derived via tendsto_nhds_unique. Truncation convergence, centering, the predictable module structure, and chaos orthogonality derived from the compensated-integral interface. The first Poisson chaos realized concretely on (ℕ, poissonMeasure) with orthogonality proved via tsum_mul_left. The LÂČ Cauchy estimate for the Δ → 0 approximation proved, with the M → ∞ direction documented as requiring Lp (not LÂČ) convergence. Part 3 — Banach energy space framework: The operator-covariant derivative D constructed via mk_dual (not axiomatized). The fluctuation factorization (Theorem A), representability obstruction, product rule with jump defect (Theorem B), and chaos characterization (Theorem C) verified. The centered obstruction witness derived from primitive stable-noise data: evenness from absolute-jump structure, positive variance from λ > 0 and T > 0 via mul_pos, nonzero from positive variance, and the obstruction from representability_obstruction. The Hilbert bridge showing the Banach framework specializes when the jump defect vanishes. The remaining primitive inputs are concentrated in two places: the Banach-side Lp-convergence layer for the compensated integral as M → ∞, and a full bottom-up Poisson-random-measure realization. These are isolated as explicit structure fields rather than hidden proof gaps. Together with the companion OperatorDerivative.lean (5,184 lines, zero sorry, one axiom) for the Hilbert paper, this constitutes 7,623 lines of formally verified stochastic calculus. To our knowledge, the Poisson mean and variance identities, the first Poisson chaos orthogonality, and the compound Poisson ItĂŽ formula via finite telescoping are among the first such formalized results in Lean 4.

Open access
2 source records
Random Matrices and Applications
Stochastic processes and financial applications
Probability and Risk Models
Original source
Mar 16, 2026·arXiv (Cornell University)
0 cites
Normal approximation for the polynomial functionals of correlated random field sampling along random walk path in dimension $1+1$

Ao Huang, Guanglin Rang, Zhonggen Su

Let $Ο$ be the stationary occupation field generated by a Poisson system of independent simple symmetric random walks on $\mathbb Z$ in space--time dimension $1+1$. For a finite set $A\subset\mathbb Z$, we consider the classical fixed-region observables $W_N(A)$, the cumulative occupation of $A$ up to time $N$, and $D_N(A)$, the number of distinct particles visiting $A$ up to time $N$. We prove quantitative central limit theorems for both observables, with Wasserstein rate of order $N^{-1/4}$. In addition, we introduce an independent nearest-neighbour random walk $S=(S_n,\,n\ge 0)$ on $\mathbb Z$ with non-zero drift and sample the field along this ballistic path. For a fixed polynomial observable $φ(x)=\sum_{j=0}^k ÎČ_j x^j, ÎČ_k\neq 0$, of degree $k\in \mathbb N$, we consider the partial sums $Y_{N,φ}=\sum_{n=1}^N φ(Ο(n,S_n)).$ We prove a Wasserstein bound of order $N^{-1/2}$ for the normal approximation of the standardized $Y_{N,φ}$. To the best of our knowledge, this is the first quantitative normal approximation result for polynomial functionals of the Poisson occupation field sampled along a random walk path. The drift induces an effective decorrelation of the sampled environment, leading to a substantial improvement over fixed-region sampling. The proofs rely on a representation of $Ο$ as a Poisson functional on path space and on the Malliavin--Stein method for Poisson functionals.

Open access
2 source records
Random Matrices and Applications
Point processes and geometric inequalities
Geometry and complex manifolds
Original source
Jan 1, 2026·SSRN Electronic Journal
0 cites
DeFi Liquidations Cluster Across Protocols in a Multivariate Hawkes Framework

Dung Cao, Palaash Gang

Cascading liquidations across decentralized finance (DeFi) lending protocols represent a systemic risk that standard empirical models often fail to capture. To quantify this phenomenon, we apply a 3-variate Hawkes process to model crossprotocol liquidation clustering among Aave V3, Compound V3, and Morpho on Ethereum. Using 7,500 on-chain liquidation events spanning 2023-01-01 through 2025-12-31, we estimate exponential triggering kernels via maximum likelihood estimation and validate the approach against nonparametric spectral estimates. The results indicate a stable, subcritical regime (ρ = 0.725) characterized by statistically significant off-diagonal excitation. The strongest cross-protocol channel runs from Morpho to Compound V3 (branching ratio Γ = 0.418), while selfexcitation ratios range from 0.28 to 0.32. Directional predictive dependence tests confirm asymmetric spillover effects. Furthermore, likelihood-based comparisons demonstrate that crossprotocol excitation significantly outperforms self-excitation-only and common-factor baselines, including models with ETH return controls. Placebo permutations verify that this off-diagonal structure is not an artifact of shared timing. Ultimately, while the findings document robust cross-protocol clustering consistent with spillover channels, we emphasize that Hawkes crossexcitation captures directional predictive dependence rather than strict structural causation.

Open access
Point processes and geometric inequalities
Random Matrices and Applications
Stochastic processes and financial applications
Original source
Jan 1, 2023·SSRN Electronic Journal
5 cites
Trading and Wealth Evolution in the Proof of Stake Protocol

Wenpin Tang

With the increasing adoption of the Proof of Stake (PoS) blockchain, it is timely to study the economy created by such blockchain. In this chapter, we will survey recent progress on the trading and wealth evolution in a cryptocurrency where the new coins are issued according to the PoS protocol. We first consider the wealth evolution in the PoS protocol assuming no trading, and focus on the problem of decentralisation. Next we consider each miner's trading incentive and strategy through the lens of optimal control, where the miner needs to trade off PoS mining and trading. Finally, we study the collective behavior of the miners in a PoS trading environment by a mean field model. We use both stochastic and analytic tools in our study. A list of open problems are also presented.

Open access
5 source records
Law, logistics, and international trade
European and International Contract Law
Diverse Legal and Medical Studies
Original source
May 17, 2021·ACM SIGMETRICS Performance Evaluation Review
22 cites
Predicting confirmation times of Bitcoin transactions

Rowel GĂŒndlach, Martijn Gijsbers, David Koops, Jacques Resing

We study the distribution of confirmation times of Bitcoin transactions, conditional on the size of the current memory pool. We argue that the time until a Bitcoin transaction is confirmed resembles the time to ruin in a corresponding Cramer-Lundberg process. This well-studied model gives mathematical insights in the mempool behaviour over time. Specifically, for situations where one chooses a fee, such that the total size of incoming transactions with higher fee is close to the total size of transactions leaving the mempool (heavy traffic), a diffusion approximation leads to an inverse Gaussian distribution for the confirmation times. The results of this paper are particularly interesting for users that want to make a Bitcoin transaction during heavy-traffic situations, as evaluation of the well-known inverse Gaussian distribution is computationally straightforward.

Blockchain Technology Applications and Security
Complex Systems and Time Series Analysis
Random Matrices and Applications
Original source
Apr 1, 2021·Naval Research Logistics (NRL)
3 cites
On fair designs of c ross‐chain exchange for cryptocurrencies via Monte Carlo simulation

Zini Wang, Guangxin Jiang, Qiang Ye

Abstract Cryptocurrency is one of the earliest and the most successful applications of blockchain, and it utilizes the distributed ledger, which is a commonly used technique in blockchain, to make a decentralized transaction within the blockchain of a cryptocurrency. However, how to make a decentralized transaction of cryptocurrencies between parties on different blockchains, that is, the cross‐chain exchange, is not well‐studied. In this paper, we develop a new method to make cross‐chain exchanges based on the classical atomic swap. We first study the optionality embedded into the atomic swap and propose to add a premium into the atomic swap, and then design a new procedure with the premium to guarantee the fairness of the cross‐chain exchange. We also provide an algorithm based on the least‐squares Monte Carlo method to estimate the premium and analyze the convergence of the algorithm. Moreover, we study the cross‐chain exchange with margin trading. We propose an adapted exchange procedure to make a fair cross‐chain exchange and an algorithm to estimate the fair premium under the margin trading. Numerical experiments are provided to show the effectiveness of the algorithms.

Stochastic processes and financial applications
Blockchain Technology Applications and Security
Random Matrices and Applications
Original source
Sep 25, 2018·The Annals of Probability
6 cites
Lower bounds for the smallest singular value of structured random matrices

Nicholas A. Cook

We obtain lower tail estimates for the smallest singular value of random matrices with independent but nonidentically distributed entries. Specifically, we consider $n\times n$ matrices with complex entries of the form \[M=A\circ X+B=(a_{ij}\xi_{ij}+b_{ij}),\] where $X=(\xi_{ij})$ has i.i.d. centered entries of unit variance and $A$ and $B$ are fixed matrices. In our main result, we obtain polynomial bounds on the smallest singular value of $M$ for the case that $A$ has bounded (possibly zero) entries, and $B=Z\sqrt{n}$ where $Z$ is a diagonal matrix with entries bounded away from zero. As a byproduct of our methods we can also handle general perturbations $B$ under additional hypotheses on $A$, which translate to connectivity hypotheses on an associated graph. In particular, we extend a result of Rudelson and Zeitouni for Gaussian matrices to allow for general entry distributions satisfying some moment hypotheses. Our proofs make use of tools which (to our knowledge) were previously unexploited in random matrix theory, in particular SzemerĂ©di’s regularity lemma, and a version of the restricted invertibility theorem due to Spielman and Srivastava.

Open access
Random Matrices and Applications
Stochastic processes and statistical mechanics
Advanced Combinatorial Mathematics
Original source
Aug 25, 2016·arXiv (Cornell University)
0 cites
Lower bounds for the smallest singular value of structured random\n matrices

Nicholas A. Cook

We obtain lower tail estimates for the smallest singular value of random\nmatrices with independent but non-identically distributed entries.\nSpecifically, we consider $n\\times n$ matrices with complex entries of the form\n\\[ M = A\\circ X + B = (a_{ij}\\xi_{ij} + b_{ij}) \\] where $X=(\\xi_{ij})$ has iid\ncentered entries of unit variance and $A$ and $B$ are fixed matrices. In our\nmain result we obtain polynomial bounds on the smallest singular value of $M$\nfor the case that $A$ has bounded (possibly zero) entries, and $B= Z\\sqrt{n}$\nwhere $Z$ is a diagonal matrix with entries bounded away from zero. As a\nbyproduct of our methods we can also handle general perturbations $B$ under\nadditional hypotheses on $A$, which translate to connectivity hypotheses on an\nassociated graph. In particular, we extend a result of Rudelson and Zeitouni\nfor Gaussian matrices to allow for general entry distributions satisfying some\nmoment hypotheses. Our proofs make use of tools which (to our knowledge) were\npreviously unexploited in random matrix theory, in particular Szemer\\'edi's\nRegularity Lemma, and a version of the Restricted Invertibility Theorem due to\nSpielman and Srivastava.\n

Open access
Random Matrices and Applications
Stochastic processes and statistical mechanics
Markov Chains and Monte Carlo Methods
Original source
Nov 27, 2015·arXiv (Cornell University)
9 cites
Universality of the mean number of real zeros of random trigonometric polynomials under a weak Cramer condition

JĂŒrgen Angst, Guillaume Poly

We investigate the mean number of real zeros over an interval $[a,b]$ of a random trigonometric polynomial of the form $\sum_{k=1}^n a_k \cos(kt)+b_k \sin(kt)$ where the coefficients are i.i.d. random variables. Under mild assumptions on the law of the entries, we prove that this mean number is asymptotically equivalent to $\frac{n(b-a)}{π\sqrt{3}}$ as $n$ goes to infinity, as in the known case of standard Gaussian coefficients. Our principal requirement is a new Cramer type condition on the characteristic function of the entries which does not only hold for all continuous distributions but also for discrete ones in a generic sense. To our knowledge, this constitutes the first universality result concerning the mean number of zeros of random trigonometric polynomials. Besides, this is also the first time that one makes use of the celebrated Kac-Rice formula not only for continuous random variables as it was the case so far, but also for discrete ones. Beyond the proof of a non asymptotic version of Kac-Rice formula, our strategy consists in using suitable small ball estimates and Edgeworth expansions for the Kolmogorov metric under our new weak Cramer condition, which both constitute important byproducts of our approach.

Open access
Geometry and complex manifolds
Advanced Algebra and Geometry
Random Matrices and Applications
Original source
May 20, 2015·Performance Evaluation
228 cites
Bitcoin blockchain dynamics: The selfish-mine strategy in the presence of propagation delay

Johannes Göbel, Paul Keeler, A. E. Krzesinski, Peter Taylor

In the context of the `selfish-mine' strategy proposed by Eyal and Sirer, we study the effect of propagation delay on the evolution of the Bitcoin blockchain. First, we use a simplified Markov model that tracks the contrasting states of belief about the blockchain of a small pool of miners and the `rest of the community' to establish that the use of block-hiding strategies, such as selfish-mine, causes the rate of production of orphan blocks to increase. Then we use a spatial Poisson process model to study values of Eyal and Sirer's parameter $Îł$, which denotes the proportion of the honest community that mine on a previously-secret block released by the pool in response to the mining of a block by the honest community. Finally, we use discrete-event simulation to study the behaviour of a network of Bitcoin miners, a proportion of which is colluding in using the selfish-mine strategy, under the assumption that there is a propagation delay in the communication of information between miners.

Open access
3 source records
Blockchain Technology Applications and Security
cs.CR
Complex Network Analysis Techniques
Original source
Jan 1, 2008·OpenGrey (Institut de l'Information Scientifique et Technique)
2 cites
The symmetric eigenvalue problem : stochastic perturbation theory and some network applications

Zhivko Stoyanov

This thesis is concerned with stochastic perturbation theory of the symmetric eigen-value problem. In particular, we provide results about the probability of interchanges in the ordering of the eigenvalues and changes in the eigenvectors of symmetric matrices subject to stochastic perturbations. In this analysis we use a novel combination of traditional Numerical Linear Algebra, Perturbation Theory and Probability Theory. The motivation for this study arises from reliability of spectral clustering of networks, when network data is subject to noise. As far as we are aware, there is nothing comparable in the literature. Further, we make conjectures from which we derive an asymptotic relation between the distributions of the largest eigenvalue and the 2-norm of random symmetric ma- trices, whose entries above the main diagonal are independent, identically distributed random variables with probability density functions being symmetric with respect to zero, including matrices from the Gaussian Orthogonal Ensemble (GOE). As far as we know, some of these conjectures are not new (possibly only as conjectures) but we are not aware of any proofs. Also, we consider networks of coupled oscillators. In their analysis we use both, knowledge of dynamical systems and spectral properties of non-negative matrices. As a result, we present an algorithm, which uncovers the \\master-slave" structure of the network. With its help, the analysis of the dynamics and the entrainment of the entire network can be reduced to considering only few of the oscillators, those whose dynamics determine the behaviour of the rest. This can be helpful in large networks exhibiting the \\master-slave" structure. Finally, we consider similarities of spectral clustering with respect to diÂźerent matrices which can be associated with a given network. In particular, we compare clustering of products of Path graphs with respect to two diÂźerent matrices: the Laplacian and the Normalised Laplacian matrices of the graph. We make the comparison by constructing a Homotopy between two eigenvalue problems and, using some Linear Algebra techniques, we show that the two matrices give similar spectral clusterings when applied to products of Path graphs.

Open access
Topological and Geometric Data Analysis
Complex Network Analysis Techniques
Random Matrices and Applications
Original source
Oct 1, 1970·The Annals of Mathematical Statistics
76 cites
An Operator Theorem on $L_1$ Convergence to Zero with Applications to Markov Kernels

Donald Ornstein, Louis Sucheston

A recent theorem of Orey [12] (see also [1], [6], [7], [13]) asserts that if $T$ is an $L_1$ operator induced on a discrete measure space by an irreducible recurrent aperiodic Markov matrix, then the condition (C) holds: $f \epsilon L_1, \int f = 0$ implies that $T^n f$ converges to zero in $L_1$. In an attempt to determine when (C) holds for more general operators, we at first prove the following (Theorem 1.1): Let $T$ be a positive linear contraction operator on $L_1$; if $T^nf$ and $T^{n+1}f$ intersect slightly, but uniformly in $f$ in the unit sphere of $L_1$, then $T^nf - T^{n+1}f$ converges to zero in norm. (C) follows if $T$ is conservative and ergodic (Corollary 1.3). In Section 2 we derive from this a simple proof of Orey's theorem. The main result of the paper is in Section 3 and could be called a "zero-two" theorem: Let $P(x, A)$ be a Markov kernel, and assume that there is a $\sigma$-finite measure $m$ such that for each $A, m(A) = 0$ implies $P(x, A) = 0$ a.e. and $m(A) > 0$ implies $\sum^\infty_{n=0} P^{(n)}(x, A) = \infty$ a.e. Then the total variation of the measure $P^{(n)}(x, \cdot) - P^{(n+1)}(x, \cdot)$ is either a.e. 2 for all $n$ or it converges a.e. to 0 as $n \rightarrow \infty$. In Section 4 it is shown that a version of the zero-two theorem essentially contains the Jamison-Orey generalization of Orey's theorem to Harris processes. Section 1 and Section 2 of this paper do not assume any knowledge of either operator ergodic theory or probability. Some known results in ergodic theory are applied in Section 3, but the proof of the main theorem does not depend on them.

Open access
Holomorphic and Operator Theory
Random Matrices and Applications
Spectral Theory in Mathematical Physics
Original source