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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.

168,742 papers · 148 categories

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57114171228 · Jun 202619922001200920172026
48 results for unitary manifolds

Study circle actions on unitary manifolds with discrete fixed points.

problem Understanding circle actions on compact unitary manifolds with discrete fixed points.
method Prove relationships between weights at fixed points and derive results regarding the first equivariant Chern class and Hirzebruch χyχ_y-genus.
result Derive a multigraph encoding fixed point data, leading to new insights into unitary S1S^1-manifolds.

We construct a new family of toric manifolds generating the unitary bordism ring. Each manifold in the family is the complex projectivisation of the sum of a line bundle and a trivial bundle over a complex projective space. We also construct a family of special unitary quasitoric manifolds which contains polynomial gen…

2014-12-16abs ↗pdf ↗

The study shows ergodicity of unitary frame flows on Kähler manifolds with specific curvature conditions.

problem Ergodicity of unitary frame flows on Kähler manifolds with negative holomorphic sectional curvature.
method Analysis of the unitary frame flow on the principal U(m)-bundle of unitary frames.
result For even-dimensional Kähler manifolds with negative λ(m)-pinched holomorphic sectional curvature, the unitary frame flow is ergodic and mixing.

Study on determinants of unitary Brownian motion and their asymptotic laws.

problem Understanding determinants of unitary Brownian motion and their behavior over time.
method Using Stiefel fibration and skew-product decomposition of the Stiefel Brownian motion.
result Prove asymptotic laws for determinants of block entries of unitary Brownian motion.

The paper proves that a specific manifold is unitary cobordant to S^2 × S^6.

problem Characterizing 8D almost complex manifolds with 4 fixed points.
method Analyzing Chern numbers and Hirzebruch χyχ_y-genus.
result An 8D compact almost complex manifold with 4 fixed points is unitary cobordant to S^2 × S^6.

Recurrent neural networks are powerful models for processing sequential data, but they are generally plagued by vanishing and exploding gradient problems. Unitary recurrent neural networks (uRNNs), which use unitary recurrence matrices, have recently been proposed as a means to avoid these issues. However, in previous …

2016-10-31abs ↗pdf ↗

We construct projective unitary representations of the smooth Deligne cohomology group of a compact oriented Riemannian manifold of dimension 4k+1, generalizing positive energy representations of the loop group of the circle. We also classify such representations under a certain condition. The number of the equivalence…

2005-10-10abs ↗pdf ↗

The conjecture of Kosniowski asserts that if the circle acts on a compact unitary manifold MM with a non-empty fixed point set and MM does not bound a unitary manifold equivariantly, then the dimension of the manifold is bounded above by a linear function on the number of fixed points. We confirm the conjecture for a…

2018-12-29abs ↗pdf ↗

Novel M-theory approach classifies topological phases of matter.

problem Classifying and understanding topological phases of matter.
method Establishing a correspondence between (2+1)d topological field theories and non-hyperbolic 3-manifolds, identifying topological phases from internal wrapped 3-manifolds.
result Paves a new route toward the classification of topological phases of matter, including fermionic and non-unitary phases.

Characterizes optimal-speed quantum state evolution Hamiltonians.

problem Optimal-speed unitary time evolution of pure and quasi-pure quantum states.
method Construction of the manifold of pure states and isometry with flag manifold, characterization of equigeodesic vectors.
result Hamiltonians generating optimal-speed time evolution are fully characterized by equigeodesic vectors of the flag manifold.

Study of unitary and groupoid orbits of normal operators, focusing on manifold structures and spectral conditions.

problem Understanding the manifold structures of orbits of normal operators under different norm topologies.
method Unified treatment of unitary and groupoid orbits, using moment maps and conditional expectations.
result Differentiable structures for orbits and necessary spectral conditions for norm closure and submanifold properties.

Clarifies the structure of quantum states using algebraic methods.

problem Unclear stratification of quantum states in physics literature.
method Analyzes the state space S(A) of a finite-dimensional C*-algebra A, focusing on unitary orbits and their properties.
result Identifies a natural Whitney stratification of the state space into matrices of fixed rank, providing a pseudo-manifold structure.

We construct a 2+1 dimensional classical gauge theory on manifolds with spin structure whose action is a refinement of the Atiyah-Patodi- Singer eta-invariant for twisted Dirac operators. We investigate the properties of the Lagrangian field theory for closed, spun 3-manifolds and compact, spun 3-manifolds with boundar…

2005-04-25abs ↗pdf ↗

We systematically develop a transform of the Fourier-Mukai type for sheaves on symplectic manifolds XX of any dimension fibred in Lagrangian tori. One obtains a bijective correspondence between unitary local systems supported on Lagrangian submanifolds of XX and holomorphic vector bundles with compatible unitary conn…

2001-05-24abs ↗pdf ↗

In 1974, Berezin proposed a quantum theory for dynamical systems having a Kähler manifold as their phase space. The system states were represented by holomorphic functions on the manifold. For any homogeneous Kähler manifold, the Lie algebra of its group of motions may be represented either by holomorphic differential …

1994-07-15abs ↗pdf ↗

The Hilbert manifold ΣΣ consisting of positive invertible (unitized) Hilbert-Schmidt operators has a rich structure and geometry. The geometry of unitary orbits ΩΣΩ\subset Σ is studied from the topological and metric viewpoints: we seek for conditions that ensure the existence of a smooth local structure for the set $…

2008-08-07abs ↗pdf ↗

Main Theorem (3.3): Let MM be a compact four-dimensional manifold either with curvature, positive on complex isotropic two-planes, or self-dual of positive scalar curvature. If π1(M)π_1 (M) admits a nontrivial unitary representation, and MM is orientable, then there exists a surjective homomorphism from π1(M)π_1 (M) on $\b…

1995-03-28abs ↗pdf ↗

Let M2nM^{2n} be a unitary torus (2n)(2n)-manifold, i.e., a (2n)(2n)-dimensional oriented stable complex connected closed TnT^n-manifold having a nonempty fixed set. In this paper we show that MM bounds equivariantly if and only if the equivariant Chern numbers <(c1Tn)i(c2Tn)j,[M]>=0< (c_1^{T^n})^i(c_2^{T^n})^j, [M]>=0 for all $i, j\in {\Bbb …

2011-03-31abs ↗pdf ↗

Quantum neural networks need both data-dependent and trainable unitaries for effective geometric deformation.

problem Quantum neural networks lack the geometric flexibility of classical networks due to limitations in state reachability.
method Viewing quantum states as embedded manifolds, we analyze infinitesimal unitary actions and introduce the CLA maps and aCLS criterion.
result Geometric flexibility in quantum neural networks requires a joint dependence on data and trainable weights.

We formulate the unitary rational orbifold conformal field theories in the algebraic quantum field theory framework. Under general conditions, we show that the orbifold of a given unitary rational conformal field theories generates a unitary modular category. Many new unitary modular categories are obtained. We also sh…

2000-04-24abs ↗pdf ↗

This is a second paper in a series devoted to the minimal unitary representation of O(p,q). By explicit methods from conformal geometry of pseudo-Riemannian manifolds, we find the branching law corresponding to restricting the minimal unitary representation to natural symmetric subgroups. In the case of purely discrete…

2001-11-07abs ↗pdf ↗

We define the twisted Blanchfield pairing of a symmetric triad of chain complexes over a group ring Z[G], together with a unitary representation of G over an Ore domain with involution. We prove that the pairing is sesquilinear, and we prove that it is hermitian and nonsingular under certain extra conditions. A twisted…

2016-05-22abs ↗pdf ↗

A major challenge in the training of recurrent neural networks is the so-called vanishing or exploding gradient problem. The use of a norm-preserving transition operator can address this issue, but parametrization is challenging. In this work we focus on unitary operators and describe a parametrization using the Lie al…

2016-07-17abs ↗pdf ↗

A non-singular sesquilinear form is constructed that is preserved by the Lawrence-Krammer representation. It is shown that if the polynomial variables q and t of the Lawrence-Krammer representation are chosen to be appropriate algebraically independant unit complex numbers, then the form is negative-definite Hermitian.…

2002-02-23abs ↗pdf ↗

With the usual definition of a super Hilbert space and a super unitary representation, it is easy to show that there are lots of super Lie groups for which the left-regular representation is not super unitary. I will argue that weakening the definition of a super Hilbert space (by allowing the super scalar product to b…

2017-11-01abs ↗pdf ↗

Random matrix ensembles yield uniform distributions on manifolds.

problem Understanding distributions of vectors in random matrix ensembles.
method Analyzing eigenvalues, singular values, and Autonne-Takagi vectors of various random matrix ensembles.
result Uniform distributions on specific manifolds for different types of random matrix ensembles.

The Hardy space H^2(R) for the upper half plane together with a unimodular function group representation u(λ) = \exp(i(λ_1ψ_1 + ... + λ_nψ_n)) for λin R^n, gives rise to a manifold M of orthogonal projections for the subspaces u(λ)H^2(R) of L^2(R). For classes of admissible functions ψ_i the strong operator topology cl…

2007-09-13abs ↗pdf ↗

Given two unitary involutions σ1σ_{1} and σ2σ_{2} satisfying Gσi=σiGG σ_{i} = - σ_{i} G on kerBker B on a compact manifold with cylindrical end, M. Lesch, K. Wojciechowski ([LW]) and W. Müller ([M]) established the formula describing the difference of two eta-invariants with the APS boundary conditions associated with σ1σ_{1}

2004-08-13abs ↗pdf ↗