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. 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. The article introduces a new convergence concept for Lorentzian spaces and applies it to generalized cones.
problem Stability of curvature bounds in generalized Lorentzian cones.
method Introduces ℓ-convergence for Lorentzian pre-length spaces, applies it to generalized cones, and proves stability of curvature bounds. result Sharp timelike curvature and curvature-dimension bounds for generalized cones are established.
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. 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.
Recursion formula derived for moduli spaces of hyperbolic surfaces with cone points.
problem Computing volumes of moduli spaces of hyperbolic surfaces with specific boundary and cone points.
method Using generalized McShane's identities, derived a recursion formula for volumes.
result Obtained a recursion formula for volumes of moduli spaces of hyperbolic surfaces.
Paper revisits DP-SCO in Euclidean and ℓpd spaces, focusing on constrained and bounded sets.
problem Differentially private stochastic convex optimization in constrained and bounded sets in Euclidean and ℓpd spaces. method Proposes methods achieving excess population risks dependent on Gaussian width of the constraint set, and novel algorithms for unconstrained and heavy-tailed data.
result Theoretical results for DP-SCO in ℓpd spaces, including optimal bounds for strongly convex functions. Researchers analyze geodesic complexity in robot paths on tree graphs.
problem Understanding optimal paths for robots on tree graphs.
method Examined geodesic complexity in ordered and unordered configuration spaces of graphs in ℓ1 and ℓ2 metrics, finding explicit geodesics and families. result Geodesic complexity matches topological complexity in all cases studied.
Igarashi introduce the concept of (α,β)-metric in Cartan space ℓn analogously to one in Finsler space and obtained the basic important geometric properties and also investigate the special class of the space with (α,β)-metric in ℓn in terms of ′invariants′. In the present paper we determine th…
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 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…
The paper proposes a novel MKL approach for OCC using ℓp-norm constraints.
problem Addressing the MKL problem for one-class classification.
method A min-max saddle point Lagrangian optimisation problem is formulated and solved efficiently.
result The proposed method outperforms baselines and other algorithms on various data sets.
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.
For an infinite cardinal κ let ℓ2(κ) be the linear hull of the standard othonormal base of the Hilbert space ℓ2(κ) of density κ. We prove that a non-separable convex subset X of density κ in a locally convex linear metric space if homeomorphic to the space (i) ℓ2f(κ) if and only if X can be…
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…
The study examines spaces of holomorphic sections vanishing along subvarieties in complex spaces.
problem Analyzing the dimensions of spaces of holomorphic sections vanishing along subvarieties in complex spaces.
method Using complex geometry and analytic subsets, the study examines the dimensions of spaces of holomorphic sections vanishing along subvarieties.
result Conditions on subvarieties ensure the dimension of spaces of holomorphic sections extending from subvarieties.
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…
Estimates Bergman kernel for Siegel varieties, focusing on geodesic distances.
problem Estimating the Bergman kernel for complex manifolds of Siegel varieties.
method Analyzes geodesic distances and derives estimates for the Bergman kernel.
result Derives estimates of the Bergman kernel for Siegel varieties.
Study sparse function recovery from indirect noisy observations using ℓ1-regularization.
problem Recovering sparse functions from indirect, noisy observations.
method Proposes an ℓ1-regularized empirical risk minimizer and analyzes its statistical properties. result Established almost-sure consistency and derived high-probability convergence rates in prediction and ℓ1 norms. Study of η invariants on lens spaces detects distinctions invisible to ordinary η.
problem Detecting distinctions in η invariants on lens spaces. method Spin-Fourier residues and equivariant η invariants. result Second derivative of the residual η germ is nonzero for some lens spaces. 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. Study examines stability of image-reconstruction algorithms using variational regularization.
problem Stability and robustness of image-reconstruction algorithms in medical imaging.
method Review and novel stability results for ℓp-regularized linear inverse problems, focusing on p∈(1,∞). result Guarantees Lipschitz continuity for small p and Hölder continuity for larger p in Lp(Ω) function spaces. We prove the following new characterization of Cp (Lipschitz) smoothness in Banach spaces. An infinite-dimensional Banach space X has a Cp smooth (Lipschitz) bump function if and only if it has another Cp smooth (Lipschitz) bump function f such that f′(x)=0 for every point x in the interior of the …
Feature hashing and other random projection schemes are commonly used to reduce the dimensionality of feature vectors. The goal is to efficiently project a high-dimensional feature vector living in Rn into a much lower-dimensional space Rm, while approximately preserving Euclidean norm. These sc…
Introduces arithmetic analogues of Orr invariants and spaces for absolute Galois groups.
problem Understanding arithmetic properties of absolute Galois groups through analogies with mapping class groups.
method Introduces arithmetic pro-ℓ Orr invariants and spaces, and investigates their properties and relations. result Determines the rank of the pro-ℓ Orr space as a Zℓ-module. Given a Hitchin representation $ρ\colon π_1(S) \to \PSL_n(\mathbb{R})$, we construct n continuous functions $\ell_i^ρ\colon \mathcal \CH(S) \to \mathbb{R}$ defined on the space of Hölder geodesic currents $\CH(S)$ such that, for a closed, oriented curve γ in S, the i--th eigenvalue of the matrix $ρ(γ)\in \PSL_n…
Improves safety region certification for smoothed classifiers without changing smoothing scheme.
problem Certified safety regions for smoothed classifiers are often small compared to optimal.
method Generalizes certified radius calculation as nested optimization problem, uses 0th-1st order information, and designs efficient estimators.
result Certified safety regions are significantly larger than current methods, achieving significant improvements on various metrics.
New algorithm reduces matrix multiplication time for sparse matrices.
problem Efficiently multiply large sparse matrices with limited space.
method Exploits sparsity to reduce QR decompositions and time complexity.
result Time complexity reduced to $\widetilde{O}\left((
nz(X)+
nz(Y))\ell+n\ell^2
ight)$ in expectation.
New explicit Calabi-Yau metrics and Kähler-Ricci solitons found on complex n-space.
problem Constructing new explicit Calabi-Yau metrics and Kähler-Ricci solitons.
method Continuous (ℓ−1)-parameter family of explicit complete gradient steady Kähler-Ricci solitons on Cn with Hamiltonian 2-forms. result Construction of new complete gradient steady Kähler-Ricci solitons with positive sectional curvature.
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…
Let X be a topological space admitting an amenable cover of multiplicity k∈N. We show that, for every n≥k and every α∈Hn(X;R), the image of α in the ℓ1-homology module Hnℓ1(X;R) vanishes. This strenghtens previous results by Gromov and Ivanov, who proved, u…
Introduces a new geometric framework for probability distributions.
problem Developing a geometric framework for probability distributions.
method Introduces ℓp-information geometry and defines the ℓ2-probability simplex via the q-root transform. result Defines a noncanonical differentiable structure and q-root map as an isometry. 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…
Let X be a compact normal complex space of dimension n, and L be a holomorphic line bundle on X. Suppose Σ=(Σ1,…,Σℓ) is an ℓ-tuple of distinct irreducible proper analytic subsets of X, τ=(τ1,…,τℓ) is an ℓ-tuple of positive real numbers, and consider the space H00(X,Lp)…
Introduces new geometric framework for probability densities on manifolds.
problem Developing a new geometric framework for probability densities on manifolds.
method Introduces ℓp-information geometry and defines ℓ2-probability simplex with q-root transform. result Explicit solution of gradient flow and geodesic completeness of e-connection. Novel framework improves randomized smoothing for various norms.
problem Developing robust defenses against adversarial attacks.
method Proposed a novel framework for devising and analyzing randomized smoothing schemes.
result Significantly improved certified accuracy in ℓ1 on standard datasets.
Twists agrarian and ℓ2-Betti numbers for locally indicable groups.
problem Understanding ℓ2-Betti numbers of locally indicable groups. method Using generalised agrarian invariants and twisted Alexander-Thurston norms.
result Twisted ℓ2-Betti numbers are equal to usual ℓ2-Betti numbers rescaled by the dimension of the twisting representation. 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 …
A TCL framework improves causal effect estimation in limited data.
problem Improving causal effect estimation accuracy in limited data.
method Transfer Learning (TCL) with ℓ1 regularization for nuisance models.
result Non-asymptotic recovery guarantees for exttt{ℓ1-TCL} in high-dimensional settings. Dictionaries are collections of vectors used for representations of elements in Euclidean spaces. While recent research on optimal dictionaries is focussed on providing sparse (i.e., ℓ0-optimal,) representations, here we consider the problem of finding optimal dictionaries such that representations of samples of …
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…
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…
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…
We give improved algorithms for the ℓp-regression problem, minx∥x∥p such that Ax=b, for all p∈(1,2)∪(2,∞). Our algorithms obtain a high accuracy solution in O~p(m2p+∣p−2∣∣p−2∣)≤O~p(m31) iterations, where each iteration requires s…
Dictionaries are collections of vectors used for representations of random vectors in Euclidean spaces. Recent research on optimal dictionaries is focused on constructing dictionaries that offer sparse representations, i.e., ℓ0-optimal representations. Here we consider the problem of finding optimal dictionaries …
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.
Motivated by vision tasks such as robust face and object recognition, we consider the following general problem: given a collection of low-dimensional linear subspaces in a high-dimensional ambient (image) space and a query point (image), efficiently determine the nearest subspace to the query in ℓ1 distance. We …
Let f:M2n→R2n+ℓ, n≥5, denote a conformal immersion into Euclidean space with codimension ℓ of a Kaehler manifold of complex dimension n and free of flat points. For codimensions ℓ=1,2 we show that such a submanifold can always be locally obtained in a rather simple way, na…