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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

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59118177236 · May 202619922001200920172026
48 results for direct sums

Study fibrations over S2S^2 with same singularities, showing monodromies are equivalent up to direct sums.

problem Classifying torus fibrations over S2S^2 up to fibre sum stabilisation.
method Analyzing monodromies and using direct sums with certain torus Lefschetz fibrations.
result Global monodromies of fibrations with same singularities are Hurwitz equivalent after direct sums.

Solves Demailly's system for direct sums of ample line bundles on Riemann surfaces.

problem Proving the existence of smooth solutions for Demailly's system.
method Used Demailly's system and Leray-Schauder degree theory to reduce the problem.
result Proved existence of smooth solutions for direct sums of ample line bundles.

Unified framework for stability and generalization of Push-Sum in decentralized learning over directed graphs.

problem Understanding stability and generalization of Push-Sum in decentralized learning over directed networks.
method Developed a unified uniform-stability framework for SGP algorithm, incorporating imbalance-aware consistency bounds.
result Established finite-iteration stability and optimization guarantees for convex and non-convex objectives.

Push-SAGA is a decentralized algorithm for directed graphs that converges linearly.

problem Finite-sum minimization over directed graphs with stochastic gradients.
method Combines variance reduction, gradient tracking, and consensus algorithms.
result Achieves linear convergence for smooth and strongly convex problems.

Knots can be constructed and decomposed using Murasugi sums of Seifert surfaces.

problem Understanding the structure of knots through Murasugi sums.
method Using Murasugi sums to decompose and construct knots, showing the structure of a bi-directed complete graph.
result Any knot can be a Murasugi sum of any two knots, with bounds on minimal complexity.

We present a new multiparameter resolvent trace expansion for elliptic operators, polyhomogeneous in both the resolvent and auxiliary variables. For elliptic operators on closed manifolds the expansion is a simple consequence of the parameter dependent pseudodifferential calculus. As an additional nontrivial toy exampl…

2013-06-04abs ↗pdf ↗

We examine the relationship between the (untwisted) knot Floer cube of resolutions and HOMFLY-PT homology. By using a filtration induced by additional basepoints on the Heegaard diagram for a knot KK, we see that the filtered complex decomposes as a direct sum of HOMFLY-PT homologies of various subdiagrams. Jaeger's c…

2015-08-12abs ↗pdf ↗

We show that the cobordism groups of negative codimensional folds maps contain direct sums of stable homotopy groups of Thom spaces of vector bundles like the circle and the infinite dimensional projective space. We give geometrical invariants which detect these direct summands.

2007-04-24abs ↗pdf ↗

AB-SAGA optimizes distributed optimization over directed graphs using variance reduction and stochastic weights.

problem Optimizing distributed stochastic optimization over directed graphs with stochastic weights.
method AB-SAGA combines variance reduction and network-level gradient tracking, using both row and column stochastic weights.
result AB-SAGA converges linearly to the global optimal with a constant step-size and achieves a linear speed-up over centralized methods.

Paper tackles hyper-gradient estimation in decentralized FL over time-varying networks.

problem Excessive communication costs and inability to use robust networks.
method Introduces an optimality condition and uses Push-Sum for averaging model parameters and gradients over time-varying directed networks.
result Derives a hyper-gradient estimator that operates over time-varying directed networks and converges to the true hyper-gradient.
Multicuspsmath.DG

For a given multicusp f=c(θ0,...,θi)f=c_{(θ_0,..., θ_i)} (1i)(1\le i), we present a direct sum decomposition theorem of the source space of iωˉf{}_i\barωf, where iωˉf{}_i\barωf is a higher version of the reduced Kodaira-Spencer-Mather map ωˉf\barωf. As a corollary of our direct sum decomposition theorem, we show that for any $i\in \mathb…

2011-12-09abs ↗pdf ↗

We give a formula for the radial asymptotics to all orders of the special qq-hypergeometric series known as Nahm sums at complex roots of unity. This result is used in~\cite{CGZ} to prove one direction of Nahm's conjecture relating the modularity of Nahm sums to the vanishing of a certain invariant in KK-theory. The …

2018-12-18abs ↗pdf ↗

Classifies representations up to dimension 3g-3 for surface mapping class groups.

problem Classifying representations of mapping class groups up to a certain dimension.
method Direct sum of a 2g or 2g+1 dimensional representation and a trivial one.
result Any representation up to dimension 3g-3 is a direct sum of a 2g or 2g+1 dimensional representation and a trivial one.

We provide a framework for studying the interplay between concordance and positive mutation and identify some of the basic structures relating the two. The fundamental result in understanding knot concordance is the structure theorem proved by Levine: for n>1 there is an isomorphism phi from the concordance group C_n o…

1999-12-21abs ↗pdf ↗

Novel algorithms for multi-agent reinforcement learning reduce sample complexity.

problem Efficiently learning Nash equilibria in multi-agent settings.
method Information-Directed Sampling (IDS) principles applied to multi-agent reinforcement learning.
result Sample-efficient algorithms for learning Nash equilibria in various multi-agent settings.

The study counts units and eigenvalue patterns in SL_n(Z) and Sp_{2n}(Z) in thin tubes.

problem Counting totally real units and eigenvalue patterns in SL_n(Z) and Sp_{2n}(Z) in thin tubes.
method Analyzes directional entropy of logarithmic embeddings and eigenvalue data in thin tubes around rays.
result The number of objects grows exponentially with the directional entropy, providing bounds for conjugacy classes.

In this paper, we introduce a study of prolongations of representations of Lie groups. We obtain a faithful (one-to-one) representation of TG where G is a finite-dimensional Lie group and TG is the tangent bundle of G, by using (not necessarily faithful) representations of G. We show that tangent functions of Lie group…

2013-10-08abs ↗pdf ↗

How many bits of information are required to PAC learn a class of hypotheses of VC dimension dd? The mathematical setting we follow is that of Bassily et al. (2018), where the value of interest is the mutual information I(S;A(S))\mathrm{I}(S;A(S)) between the input sample SS and the hypothesis outputted by the learning algo…

2018-04-16abs ↗pdf ↗

We study Farrell Nil-groups associated to a finite order automorphism of a ring RR. We show that any such Farrell Nil-group is either trivial, or infinitely generated (as an abelian group). Building on this first result, we then show that any finite group that occurs in such a Farrell Nil-group occurs with infinite mu…

2014-03-27abs ↗pdf ↗

We consider semi-direct products $\C^{n}\ltimes_φN$ of Lie groups with lattices ΓΓ such that NN are nilpotent Lie groups with left-invariant complex structures. We compute the Dolbeault cohomology of direct sums of holomorphic line bundles over G/ΓG/Γ by using the Dolbeaut cohomology of the Lie algebras of the direct …

2011-07-24abs ↗pdf ↗

We show that over the binary field F2\mathbb F_2, the Bar-Natan perturbation of Khovanov homology splits as the direct sum of its two reduced theories, which we also prove are isomorphic. This extends Shumakovitch's analogous result for ordinary Khovanov homology, without the perturbation.

2015-08-24abs ↗pdf ↗

We present a novel tractable generative model that extends Sum-Product Networks (SPNs) and significantly boosts their power. We call it Sum-Product-Quotient Networks (SPQNs), whose core concept is to incorporate conditional distributions into the model by direct computation using quotient nodes, e.g. $P(A|B) = \frac{P(…

2017-10-12abs ↗pdf ↗

We construct branched double coverings by certain direct products of manifolds for connected sums of copies of sphere bundles over the 2-sphere. As an application we answer a question of Kotschick and Loeh up to dimension five. More precisely, we show that: (1) every simply connected, closed four-manifold admits a bran…

2012-10-04abs ↗pdf ↗

Decomposable arrangements have simpler topological and combinatorial properties.

problem Understanding the structure of decomposable hyperplane arrangements.
method Analyzing the Lie algebra and Alexander invariant of decomposable arrangements.
result The Alexander invariant of decomposable arrangements decomposes into local components.

Study finds conditions for minimum of Donaldson's functional on Higgs bundles with non-holomorphic Higgs fields.

problem Finding conditions for minimum of Donaldson's functional on Higgs bundles with non-holomorphic Higgs fields.
method Restriction of Donaldson's functional to diagonal metrics on Higgs bundles with non-holomorphic Higgs fields.
result Provides necessary and sufficient conditions for the functional to attain a minimum.

In this note, using Calabi's method, we construct rotationally symmetric Kahler-Ricci solitons on the total space of direct sum of fixed hermitian line bundle and its projective compactification, where the curvature of hermitian line bundle is Kahler-Einstein. These examples generalize the construction of Koiso, Cao an…

2010-04-23abs ↗pdf ↗

It is known that the bundle of Dirac spinors is produced as a direct sum of two bundles - the bundle of chiral spinors and its Hermitian conjugate bundle. In this paper some aspects of metric connections for chiral and Dirac spinors are resumed and their relation is studied.

2006-02-16abs ↗pdf ↗

Nesterov's momentum trick is famously known for accelerating gradient descent, and has been proven useful in building fast iterative algorithms. However, in the stochastic setting, counterexamples exist and prevent Nesterov's momentum from providing similar acceleration, even if the underlying problem is convex and fin…

2016-03-18abs ↗pdf ↗

We prove the bounded isometry conjecture of F. Lalonde and L. Polterovich for a special class of closed symplectic manifolds. As a byproduct, it is shown that the flux group of a product of these special symplectic manifold is isomorphic to the direct sum of the flux group of each symplectic manifold.

2010-05-31abs ↗pdf ↗

New method for inferring time series graph from sparse-group log-sum penalty.

problem Inferring conditional independence graph from high-dimensional stationary multivariate Gaussian time series.
method Sparse-group log-sum penalty (LSP) and alternating direction method of multipliers (ADMM) for iterative optimization.
result Local convergence of inverse PSD estimators to the true value with rate of convergence.

Let P(E)P(E) be the projectivization of a holomorphic vector bundle EE over a compact complex curve CC. We characterize the existence of an extremal Kähler metric on the ruled manifold P(E)P(E) in terms of relative K-polystability and the fact that EE decomposes as a direct sum of stable bundles.

2017-01-30abs ↗pdf ↗

We study direct limits (G,K)=lim(Gn,Kn)(G,K) = \varinjlim (G_n,K_n) of compact Gelfand pairs. First, we develop a criterion for a direct limit representation to be a multiplicity--free discrete direct sum of irreducible representations. Then we look at direct limits G/K=limGn/KnG/K = \varinjlim G_n/K_n of compact riemannian symmetric spaces, …

2008-01-25abs ↗pdf ↗

Resolution of a compact group action in the sense described by Albin and Melrose is applied to the conjugation action by the unitary group on self-adjoint matrices. It is shown that the eigenvalues are smooth on the resolved space and that the trivial bundle smoothly decomposes into the direct sum of global one-dimensi…

2015-04-28abs ↗pdf ↗