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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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3570105140 · May 202619922001200920172026
48 results for unitary families

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 ↗

For a compact surface S=Sg,nS = S_{g,n} with 3g+n43g + n \geq 4, we introduce a family of unitary representations of the mapping class group Mod(SS) based on the space of measured foliations. For this family of representations, we show that none of them has almost invariant vectors. As one application, we obtain an inequalit…

2019-06-04abs ↗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 ↗

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 ↗

We introduce a differential geometric framework for describing families of quantum error-correcting codes and for understanding quantum fault tolerance. This work unifies the notion of topological fault tolerance with fault tolerance in other kinds of quantum error-correcting codes. In particular, we use fibre bundles …

2013-09-26abs ↗pdf ↗

Mackey showed that for a compact Lie group KK, the pair (K,C0(K))(K,C^{0}(K)) has a unique non-trivial irreducible covariant pair of representations. We study the relevance of this result to the unitary equivalence of quantizations for an infinite-dimensional family of K×KK\times K invariant polarizations on TKT^{\ast}K. The …

2012-11-09abs ↗pdf ↗

In a "naive" attempt to create algebraic quantum field theories on the circle, we obtain a family of unitary representations of Thompson's groups T and F for any subfactor. The Thompson group elements are the "local scale transformations" of the theory. In a simple case the coefficients of the representations are polyn…

2014-12-24abs ↗pdf ↗

We show that for any positive integer nn, the maps xCn{x,zi2}i=14nR4nx \in \mathbb{C}^n \mapsto \{\left|\langle x, z_i \rangle \right|^2\}_{i=1}^{4n} \in \mathbb{R}^{4n}, where ziz_i are the columns of four n×nn\times n unitary matrices, are generically injective modulo multiplication by a global phase factor, yielding a family of emb…

2013-06-05abs ↗pdf ↗

Study on random representations of surface groups into SU(n), focusing on asymptotic expansions.

problem Understanding random representations of surface groups into special unitary groups.
method Use of a symplectic form on moduli space, establishing asymptotic expansions for trace values.
result Existence of large n asymptotic expansions for expected values of trace of elements under random representations.

Let I be a symmetrically-normed ideal of the space of bounded operators acting on a Hilbert space H. Let pi1w{p_i}_1 ^w (1w)(1\leq w \leq \infty) be a family of mutually orthogonal projections on H. The pinching operator associated with the former family of projections is given by P: I --> I, P(x)=\sum_{i=1}^{w} p_i x p_i.…

2011-05-09abs ↗pdf ↗

Paper presents a new VMBQC model with fewer parameters for better generative modeling.

problem Limited generative power of VMBQC due to more parameters than unitary models.
method Introduces a restricted VMBQC model with a single additional trainable parameter.
result Minimal extension of VMBQC model generates distributions not learnable by unitary models.

We consider a gauge invariant one parameter family of families of fiberwise twisted Dirac type operators on a fiberation with the typical fiber an even dimensional compact manifold with boundary, i.e., a family {Du},u[0,1]\{D_u\}, u\in [0,1] with D1=gD0g1D_1=gD_0g^{-1} for a suitable unitary automorphism gg of the twisted bundle. Su…

2014-10-22abs ↗pdf ↗

Modeling functional data, this study uncovers the size-and-shape of functions under noisy observations.

problem Uncertainty in recovering a fixed effect function from noisy observations.
method Bayesian functional mixed model with priors on unitary transformations.
result It is possible to recover the size-and-shape of a square-integrable function μμ.

We investigate in detail the connection between harmonic maps from Riemann surfaces into the unitary group $\U(n)$ and their Grassmannian models: these are families of shift-invariant subspaces of $L^2(S^1,\C^n)$. With the help of operator-theoretic methods we derive a criterion for finiteness of the uniton number whic…

2018-12-21abs ↗pdf ↗

We construct a Fourier--Mukai transform for smooth complex vector bundles EE over a torus bundle π:MB,π:M \to B, the vector bundles being endowed with various structures of increasing complexity. At a minimum, we consider vector bundles EE with a flat partial unitary connection, that is families or deformations of flat …

2003-07-14abs ↗pdf ↗

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 ↗

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 ↗

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.

We prove the existence of multiparameter isospectral deformations of metrics on SO(n) (n=9(n = 9 and n11)n\geq 11), SU(n) (n8)(n\geq 8), and Sp(n)Sp(n) (n4)(n\geq 4). For these examples, we follow a metric construction developed by Schueth who had given one-parameter families of isospectral metrics on orthogonal and unitary group…

2004-08-11abs ↗pdf ↗

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.

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 ↗

Otsuki tori form a countable family of immersed minimal two-dimensional tori in the unitary three-dimensional sphere. According to El Soufi-Ilias theorem, the metrics on the Otsuki tori are extremal for some unknown eigenvalues of the Laplace-Beltrami operator. Despite the fact that the Otsuki tori are defined in quite…

2011-08-25abs ↗pdf ↗

Researchers compute monodromy groups of surface families over quartic curves.

problem Computing monodromy groups of surface families over smooth quartic curves.
method Analyzing cyclic branched covers of P2\mathbb{P}^{2} over smooth quartic curves, computing monodromy groups for del Pezzo and K3 surfaces.
result Obtained monodromy groups for del Pezzo and K3 surfaces, including Weyl group $W\left(E_{7} ight)$ and arithmetic lattice $U\left(h_{L_{-}} ight)$.

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.

This paper introduces a submanifold of the moduli space of unitary representations of the fundamental group of a punctured sphere with fixed local monodromy. The submanifold is defined via products of involutions through Lagrangian subspaces. We show that the moduli space of Lagrangian representations is a Lagrangian s…

2005-06-06abs ↗pdf ↗

The aim of this talk is to explain how symmetry breaking in a quantum field theory problem leads to a study of projective bundles, Dixmier-Douady classes, and associated gerbes. A gerbe manifests itself in different equivalent ways. Besides the cohomological description as a DD class, it can be defined in terms of a fa…

2002-06-17abs ↗pdf ↗

New method for directed graphs using learnable spectral positional encodings.

problem Challenges in magnetic Laplacians and unitary gauge invariance for directed graphs.
method Learnable spectral PEs of the form hθ(Aq)R, computed in Hermitian block Krylov subspace.
result Gauge-invariant and computationally efficient solution for directed graphs.