An elementary family of local Hamiltonians H,¸ℓ,ℓ=1,2,3,ldots, is described for a 2−dimensional quantum mechanical system of spin =1/2 particles. On the torus, the ground state space G∘,ℓ is (log) extensively degenerate but should collapse under łperturbation" to an anyonic syste…
A new PCA method using Tℓ1-norm outperforms existing methods.
problem Outliers and noise sensitivity in classical PCA.
method PCA based on Tℓ1-norm maximization. result The method outperforms PCA-ℓp, ℓpSPCA, and PCA in numerical experiments. We provide recovery guarantees for compressible signals that have been corrupted with noise and extend the framework introduced in \cite{bafna2018thwarting} to defend neural networks against ℓ0-norm, ℓ2-norm, and ℓ∞-norm attacks. Our results are general as they can be applied to most unitary tr…
Paper improves ℓ0-SSC for noisy data by proving SDP and proposing Noisy-DR-ℓ0-SSC.
problem Noisy data and less restrictive subspace affinity in sparse subspace clustering.
method Proposes Noisy-DR-ℓ0-SSC, which projects data onto a lower dimensional space and then applies noisy ℓ0-SSC. result Theoretical guarantee on the correctness of noisy ℓ0-SSC in terms of SDP on noisy data. A pseudo-length function defined on an arbitrary group G=(G,⋅,e,()−1) is a map ℓ:G→[0,+∞) obeying ℓ(e)=0, the symmetry property ℓ(x−1)=ℓ(x), and the triangle inequality ℓ(xy)⩽ℓ(x)+ℓ(y) for all x,y∈G. We consider pseudo-length functions which sa…
Sparse clustering, which aims to find a proper partition of an extremely high-dimensional data set with redundant noise features, has been attracted more and more interests in recent years. The existing studies commonly solve the problem in a framework of maximizing the weighted feature contributions subject to a $\ell…
New surfaces near a sphere violate Minkowski inequality.
problem Minkowski inequality failure near a sphere.
method Constructed surfaces converging to a sphere in W2,p∩C1. result Minkowski inequality fails for perturbations of a sphere.
This paper addresses how well we can recover a data matrix when only given a few of its elements. We present a randomized algorithm that element-wise sparsifies the data, retaining only a few its elements. Our new algorithm independently samples the data using sampling probabilities that depend on both the squares ($\e…
Researchers redefine ℓ∞-cohomology for groups and spaces, linking it to amenability, hyperbolicity, and algorithmic undecidability.
problem Characterizing groups using ℓ∞-cohomology. method Revisiting Gersten's ℓ∞-cohomology, providing characterizations of amenability and hyperbolicity, and considering algorithmic problems. result Undecidability of some algorithmic problems concerning ℓ∞-cohomology. Generalized distance-squared mappings are quadratic mappings of Rm into Rℓ of special type. In the case that matrices A constructed by coefficients of generalized distance-squared mappings of R2 into Rℓ (ℓ≥3) are full rank, the generalized distance-square…
The paper analyzes ℓ1-LinR for Ising model selection using statistical mechanics.
problem Model selection consistency of ℓ1-LinR for Ising models. method Replica method from statistical mechanics, ℓ1-regularized linear regression (ℓ1-LinR). result Model selection consistency with sample complexity $M=\mathcal{O}\left(\log N
ight)$.
Fix a prime number ell. In this paper we develop the theory of relative pro-ell completion of discrete and profinite groups -- a natural generalization of the classical notion of pro-ell completion -- and show that the pro-ell completion of the Torelli group does not inject into the relative pro-ell completion of the c…
In this paper, we discuss the statistical properties of the ℓq optimization methods (0<q≤1), including the ℓq minimization method and the ℓq regularization method, for estimating a sparse parameter from noisy observations in high-dimensional linear regression with either a deterministic or rando…
The paper constructs stable minimal hypersurfaces with specific singularities.
problem Creating minimal hypersurfaces with controlled singularities.
method Constructing hypersurfaces with a given singular set in a modified Euclidean space.
result Embedded minimal hypersurfaces with stable properties and specified singularities.
Enhances robustness of AT frameworks to multiple perturbations without increasing training complexity.
problem Defending against the union of multiple perturbations in adversarial training.
method SNAP technique that augments a network with shaped noise to enhance robustness.
result 14%-to-20% improvement in adversarial accuracy for ResNet-18 on CIFAR-10.
In this paper, we propose ℓp-norm regularized models to seek near-optimal sparse portfolios. These sparse solutions reduce the complexity of portfolio implementation and management. Theoretical results are established to guarantee the sparsity of the second-order KKT points of the ℓp-norm regularized models…
Improved approximation for socially fair clustering with ℓp-objective.
problem Finding a set of centers minimizing the maximum distance to all points in each group.
method Introduced a strengthened LP relaxation with an integrality gap of Θ(loglogℓlogℓ). result Improved approximation algorithm with (eO(p)loglogℓlogℓ)-approximation. State-of-the-art subspace clustering methods are based on expressing each data point as a linear combination of other data points while regularizing the matrix of coefficients with ℓ1, ℓ2 or nuclear norms. ℓ1 regularization is guaranteed to give a subspace-preserving affinity (i.e., there are no conne…
Suppose M is a non-compact connected smooth n-manifold. Let D(M) denote the group of diffeomorphisms of M endowed with the compact-open C^\infty-topology and D^c(M) denote the subgroup consisting of diffeomorphisms of M with compact support. Let D(M)_0 and D^c(M)_0 be the connected components of id_M in D(M) and D^c(M)…
This work provides efficient algorithms for approximating ℓ_p sensitivities and related statistics.
problem Estimating the importance of datapoints in high-dimensional datasets.
method Efficient algorithms for computing α-approximation of ℓ_1 sensitivities and total sensitivity using importance sampling and sensitivity computations.
result Real-world datasets have significantly lower intrinsic effective dimensionality than theoretical predictions.
We investigate the difference between using an ℓ1 penalty versus an ℓ1 constraint in generalized eigenvalue problems, such as principal component analysis and discriminant analysis. Our main finding is that an ℓ1 penalty may fail to provide very sparse solutions; a severe disadvantage for variable sel…
Paper optimizes sparse feature selection for cancer detection using GSVP and SVM.
problem Sparse feature selection for cancer detection.
method Regularized GSVP with proximal gradient descent, feature selection via SVM.
result Near-perfect balanced accuracy with few selected features.
New algorithm solves ℓ0-norm constrained multilinear logistic regression for tensor data.
problem Non-convex and nonsmooth ℓ0-norm constraints in multilinear logistic regression. method APALM+ method for globally convergent optimization. result APALM+ ensures convergence to a first-order critical point. The paper analyzes kNN density estimation's convergence rates under different conditions.
problem Analyzing convergence rates of kNN density estimation under bounded and unbounded support conditions.
method Examined two cases: bounded support with known and unknown support sets, and unbounded support with smooth density function.
result kNN density estimation is minimax optimal under certain conditions and better than kernel density estimation in some cases.
Efficiently performs robust and sparse kernel regression.
problem Robust and sparse kernel regression.
method Sign gradient descent and early stopping.
result Sign gradient descent achieves robust and sparse kernel regression efficiently.
In this paper we consider the problem of grouped variable selection in high-dimensional regression using ℓ1−ℓq regularization (1≤q≤∞), which can be viewed as a natural generalization of the ℓ1−ℓ2 regularization (the group Lasso). The key condition is that the dimensionality pn can…
Proposes a new method for joint sample and feature selection in multi-view data.
problem Cannot detect latent subsets of samples and remove outliers.
method Weighted Sparse Partial Least Squares (ℓ∞/ℓ0-wsPLS) method for joint sample and feature selection. result Developed globally convergent algorithm and iterative algorithms for multi-view data fusion.
We study the robustness properties of ℓ1 norm minimization for the classical linear regression problem with a given design matrix and contamination restricted to the dependent variable. We perform a fine error analysis of the ℓ1 estimator for measurements errors consisting of outliers coupled with noise. We…
ALℓ0CORE tensor decomposition reduces computational cost for sparse count data.
problem Efficiently decompose sparse count data matrices.
method Probabilistic Tucker decomposition with ℓ0-norm constraint. result ALℓ0CORE achieves similar results to full Tucker decomposition at a fraction of the cost. Study homogeneous Einstein metrics on specific non-Kähler C-spaces.
problem Classify and analyze homogeneous Einstein metrics on non-Kähler C-spaces.
method Use painted Dynkin diagrams and mapping degree theory to classify and find Einstein metrics.
result Existence and classification of invariant Einstein metrics on specific spaces.
In this paper, we study the Lévy-Milman concentration phenomenon of 1-Lipschitz maps into infinite dimensional metric spaces. Our main theorem asserts that the concentration to an infinite dimensional ℓp-ball with the ℓq-distance function for 1≤p<q≤+∞ is equivalent to the concentration to the…
New MPNNs match 2-WL, faster distinguishing graphs.
problem Improving graph neural network expressiveness.
method Introducing ℓ-walk MPNNs and second-order GNNs. result Walk MPNNs match 2-WL and can distinguish graphs faster.
Safe screening rules reduce computation time in logistic regression with ℓ0−ℓ2 regularization.
problem Efficiently solving logistic regression with many features and regularization.
method Screening rules based on Fenchel dual lower bounds of strong conic relaxations.
result A high percentage of features can be safely removed before solving, leading to substantial speed-up.
Support selection and eventwise decoupling for simultaneous bets proven.
problem Optimizing expected utility for simultaneous independent events with multiple outcomes.
method Proved a support theorem for a broad class of strictly increasing strictly concave utilities, identifying the exact active support and proving independence from utility function.
result The exact active support is the eventwise union of single-event supports, independent of the utility function.
Let n be a positive integer, and let ℓ>1 be square-free odd. We classify the set of equivariant homeomorphism classes of free Cℓ-actions on the product S1×Sn of spheres, up to indeterminacy bounded in ℓ. The description is expressed in terms of number theory. The techniques are various appl…
Signal estimation problems with smoothness and sparsity priors can be naturally modeled as quadratic optimization with ℓ0-"norm" constraints. Since such problems are non-convex and hard-to-solve, the standard approach is, instead, to tackle their convex surrogates based on ℓ1-norm relaxations. In this paper…
In many applications, high-dimensional data points can be well represented by low-dimensional subspaces. To identify the subspaces, it is important to capture a global and local structure of the data which is achieved by imposing low-rank and sparseness constraints on the data representation matrix. In low-rank sparse …
Constructs generalized Frobenius manifolds for specific Weyl groups.
problem Creating structures for orbit spaces of Weyl groups.
method Applying a previously established construction method to specific Weyl groups.
result Generalized Frobenius manifold structures constructed for Aℓ,Bℓ,Cℓ and Dℓ. AdamW optimizes a constrained loss with ℓ∞ norm constraint.
problem Understanding the optimization behavior of AdamW with ℓ∞ norm constraint. method Analyzing AdamW as a smoothed version of SignGD and connecting it to Frank-Wolfe optimization.
result AdamW implicitly performs constrained optimization with ℓ∞ norm constraint. Extending work of Kapouleas and Yang, for any integers N≥2, k,ℓ≥1, and m sufficiently large, we apply gluing methods to construct in the round 3-sphere a closed embedded minimal surface that has genus kℓm2(N−1)+1 and is invariant under a Dkm×Dℓm subgroup of O(4), where …
Decomposes string links in a surface into prime components.
problem Decomposing string links in a surface into prime components.
method Proves a prime decomposition theorem for string links in a thickened surface.
result Any non-braid string link can be uniquely decomposed into prime string links up to braid equivalence.
A new algorithm speeds up EEG source localization using ℓ1 regularization.
problem Challenging inverse problem in mapping EEG readings to brain activity.
method Formulated as a graphical generalized elastic net inverse problem, solved with a variable projected algorithm (VPAL).
result VPAL provides faster and more accurate EEG source localization compared to existing methods.
We investigate the learning rate of multiple kernel learning (MKL) with ℓ1 and elastic-net regularizations. The elastic-net regularization is a composition of an ℓ1-regularizer for inducing the sparsity and an ℓ2-regularizer for controlling the smoothness. We focus on a sparse setting where the total …
Let t1,…,tn be ℓ-group terms in the variables X1,…,Xm. Let t^1,…,t^n be their associated piecewise homogeneous linear functions. Let G be the ℓ-group generated by t^1,…,t^n in the free m-generator ℓ-group Am. We prove: (i) the problem …
The paper studies the asymptotic behavior of adversarial training under ℓ∞-perturbation.
problem Theoretical guarantees for sparsity-recovery in adversarial training.
method Investigation of the asymptotic distribution of the adversarial training estimator in generalized linear models.
result The asymptotic distribution of the adversarial training estimator under ℓ∞-perturbation could have a positive probability mass at 0 when the true parameter is 0. Averages are invariants defined on the ℓ1 cohomology of Lie groups. We prove that they vanish for abelian and Heisenberg groups. This result completes work by other authors and allows to show that the ℓ1 cohomology vanishes in these cases.
Safe screening rules reduce ℓ0-regression computation by fixing 76% of variables.
problem Efficiently solving ℓ0-regression problems with large datasets. method Convex relaxation and safe screening rules to eliminate variables.
result 76% of variables can be fixed to their optimal values, reducing computational burden.
Formulae for special almost-complex structures on Vogan diagrams.
problem Existence of special almost-complex structures on almost-Kähler manifolds.
method Combinatorics of Vogan diagrams for classical semisimple Lie groups.
result Explicit formulae for special almost-complex structures.