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arXiv research

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.

168,695 papers · 148 categories

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119239358477 · Jun 202019922001200920172026
48 results for TT spaces

Using nonlinear pde techniques, we construct a new family of globally smooth tt* structures. This includes tt* structures associated to the (orbifold) quantum cohomology of a finite number of complex projective spaces and weighted projective spaces. The existence of such "magical solutions" of the tt* equations, namely…

2010-10-10abs ↗pdf ↗

New surfaces with conjugate points have global blow-down maps in their TT spaces.

problem Constructing global blow-down maps for surfaces with conjugate points.
method Explicit construction of a family of non-trapping Riemannian surfaces with global blow-down maps.
result Global blow-down maps exist for some non-simple surfaces with conjugate points.

Solves constant pre-factor problem for tt*-Toda equations using asymptotic data and symplectic structures.

problem Constant pre-factor problem for the tt*-Toda equations.
method Explicit evaluation using asymptotic data and introduction of symplectic structures.
result Preservation of symplectic structures by Riemann-Hilbert correspondence for wider class of solutions.

The paper proves an isomorphism between tttt^* structures of Landau-Ginzburg and Calabi-Yau models.

problem Establishing an isomorphism between tttt^* structures of different geometries.
method Using Landau-Ginzburg models and Calabi-Yau hypersurfaces, proving the isomorphism via the big residue map.
result An isomorphism between tttt^* structures of Landau-Ginzburg and Calabi-Yau models is proven.

The paper studies automorphisms of free groups with a North-South dynamics.

problem Characterizing automorphisms of free groups with dynamical properties.
method Analyzes the action of outer automorphisms on a relative space of currents.
result Proves the existence of a preferred compact space on which automorphisms act with North-South dynamics.

In "Isomonodromy aspects of the tt* equations of Cecotti and Vafa I. Stokes data" (arxiv:1209.2045) we described all smooth solutions of the two-function tt*-Toda equations in terms of asymptotic data, holomorphic data, and monodromy data. In this supplementary article we focus on the holomorphic data and its interpret…

2012-09-11abs ↗pdf ↗

We study possible real structures in the space of solutions to the quantum differential equation. We show that, under mild conditions, a real structure in orbifold quantum cohomology yields a pure and polarized tt^*-geometry near the large radius limit. We compute an example of P^1 which is pure and polarized over the …

2009-06-06abs ↗pdf ↗

In this note, we prove that for a cobounded,Lipschitz path $γ:I\to\TT$, if the pull back bundle Hγ\mathcal H_γ over II is a strongly relatively hyperbolic metric space then there exists a geodesic ξξ in $\TT$ such that γ(I)γ(I) and ξξ are close to each other.

2011-09-17abs ↗pdf ↗

Tensor, a multi-dimensional data structure, has been exploited recently in the machine learning community. Traditional machine learning approaches are vector- or matrix-based, and cannot handle tensorial data directly. In this paper, we propose a tensor train (TT)-based kernel technique for the first time, and apply it…

2020-01-02abs ↗pdf ↗

The big phase space, the geometric setting for the study of quantum cohomology with gravitational descendents, is a complex manifold and consists of an infinite number of copies of the small phase space. The aim of this paper is to define a Hermitian geometry on the big phase space. Using the approach of Dijkgraaf and …

2012-11-23abs ↗pdf ↗

Recent studies have introduced end-to-end TTS, which integrates the production of context and acoustic features in statistical parametric speech synthesis. As a result, a single neural network replaced laborious feature engineering with automated feature learning. However, little is known about what types of context in…

2018-11-04abs ↗pdf ↗

Study geodesic X-ray transforms on hyperbolic surfaces, proposing new reconstruction methods.

problem Inverting geodesic X-ray transforms for symmetric tensor fields on asymptotically hyperbolic surfaces.
method Developed a decomposition theorem for m-tensor fields, used Guillemin-Kazhdan operators and 0-calculus, and provided explicit reconstruction methods.
result Explicit reconstruction methods for even tensor fields from their X-ray transform or normal operator.

Tensor network surrogate for efficient option pricing in large portfolios.

problem Large-scale portfolio revaluation problems in market risk management.
method Tensor-train (TT) approximation for high-dimensional price surfaces, direct inference using Laplacian kernel and TT representations.
result Tensor surrogate achieves lower test error and faster evaluation times compared to standard GPR.

We study transverse-tracefree (TT)-tensors on conformally flat 3-manifolds (M,g)(M,g). The Cotton-York tensor linearized at gg maps every symmetric tracefree tensor into one which is TT. The question as to whether this is the general solution to the TT-condition is viewed as a cohomological problem within an elliptic com…

1996-06-18abs ↗pdf ↗

We consider the problem of estimating from sample paths the absolute spectral gap γγ_* of a reversible, irreducible and aperiodic Markov chain (Xt)tN(X_t)_{t \in \mathbb{N}} over a finite state space ΩΩ. We propose the UCPI{\tt UCPI} (Upper Confidence Power Iteration) algorithm for this problem, a low-complexity algorithm …

2018-06-15abs ↗pdf ↗

We propose RandUCB\tt RandUCB, a bandit strategy that builds on theoretically derived confidence intervals similar to upper confidence bound (UCB) algorithms, but akin to Thompson sampling (TS), it uses randomization to trade off exploration and exploitation. In the KK-armed bandit setting, we show that there are infinitel…

2019-10-11abs ↗pdf ↗

Proposes Textual Echo Cancellation to improve speech recognition.

problem Improving speech recognition performance and user experience for smart devices.
method A novel sequence-to-sequence model with multi-source attention that processes both the microphone mixture signal and source text of TTS playback.
result Demonstrates enhanced speech recognition performance and reduced latency.

Investigates neural TTS systems for Japanese and English.

problem Improving neural TTS systems for high-quality speech synthesis.
method Comparative study of neural sequence-to-sequence TTS vs. DNN pipeline TTS, varying model architecture, parameter size, and language.
result A neural sequence-to-sequence TTS system requires sufficient model parameters and a powerful encoder for high-quality speech synthesis.

We present a fully convolutional wav-to-wav network for converting between speakers' voices, without relying on text. Our network is based on an encoder-decoder architecture, where the encoder is pre-trained for the task of Automatic Speech Recognition, and a multi-speaker waveform decoder is trained to reconstruct the…

2019-04-18abs ↗pdf ↗

A new TTS method uses diffusion and VAE for better speech synthesis.

problem Improving text-to-speech synthesis for better speech quality and robustness.
method Combines diffusion probabilistic model and variational autoencoder for latent variable conversion.
result The method is robust to poor orthography and alignment errors.

CNPs improve function approximation by contrastive learning.

problem Learning from non-i.i.d function instantiations in high-dimensional, noisy spaces.
method CNPs with TCL and FCL contrastive branches for better function approximation.
result CNPs outperform other variants in function distribution reconstruction and parameter identification.

TensorGuide improves LoRA efficiency and expressivity through joint tensor-train optimization.

problem Limited expressivity and generalization of standard LoRA.
method TensorGuide uses a unified tensor-train structure with controlled Gaussian noise to generate correlated low-rank matrices.
result TensorGuide achieves superior accuracy and scalability with fewer parameters compared to standard LoRA and TT-LoRA.

A new method computes Greeks for multi-asset options using tensor trains and Fourier transforms.

problem Efficient computation of Greeks for multi-asset options with high accuracy and low sample complexity.
method Tensor train (TT) representations of Fourier-based pricing functions, combined with numerical differentiation or analytical approaches.
result Significant speed-ups of up to 105imes10^{5} imes over Monte Carlo simulations while maintaining comparable accuracy.

Establishes correspondence between Calabi-Yau and Landau-Ginzburg structures.

problem Preserving real structures in the Calabi-Yau/Landau-Ginzburg correspondence.
method Detailed analysis of period integrals and modification of real structures.
result Full CY/LG correspondence for tttt^* structures established.

Bayesian tensor train kernel machine uses Laplace approximation for scalable GP regression.

problem Scalability limitations of Gaussian process regression.
method Bayesian tensor train kernel machine with Laplace approximation and variational inference.
result VI replaces cross-validation and offers up to 65x faster training.

Paper tackles multivariate shape-constrained convex regression problems.

problem Fitting a convex function to data with component-wise monotonicity and uniform Lipschitz continuity.
method Least squares estimator via solving a constrained convex quadratic programming problem. Efficient algorithms designed: sGS-ADMM and pALM.
result Both proposed algorithms outperform state-of-the-art methods in numerical experiments.