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.
We use the supergeometric formalism, more precisely, the so-called "big bracket" (for which brackets and anchors are encoded by functions on some graded symplectic manifold) to address the theory of Jacobi algebroids and bialgebroids (following mainly Iglesias-Marrero and Grabowski-Marmo as a guideline). This formalism…
We etablish a necessary and sufficient condition under which there exists a tangential and well graded star product, differential or not, on the dual g^* of a nilpotent Lie algebra g. We also give enlightening examples with explicit computations.
We define the notion of a formal connection for a smooth family of star products with fixed underlying symplectic structure. Such a formal connection allows one to relate star products at different points in the family. This generalizes the formal Hitchin connection introduced by the first author. We establish a necess…
In this paper we prove some classification theorems of real hypersur- faces in Mn(c) satisfying certain conditions on the covariant derivative of the structure Jacobi operator. We also prove the non-existence of real hypersurfaces with Codazzi type structure Jacobi operator in Mn(c).
problem No specific problem stated; focuses on definition and properties.
method Characterizes Jacobi fields using Riemannian geometry methods and finds them explicitly. Uses complete lift and curvature/torsion of nonholonomic connection.
result Derives nonholonomic Jacobi equations in two equivalent ways.
We reformulate the notion of a Jacobi algebroid in terms of weighted odd Jacobi brackets. We then show how a Jacobi algebroid can be understood in terms of a kind of curved Q-manifold. In particular the homological condition on the odd vector field is deformed in a very specific way. This leads to the notion of a quasi…
A challenging problem in estimating high-dimensional graphical models is to choose the regularization parameter in a data-dependent way. The standard techniques include K-fold cross-validation (K-CV), Akaike information criterion (AIC), and Bayesian information criterion (BIC). Though these methods work well for lo…
If W+ denotes the self dual part of the Weyl tensor of any Kähler 4-manifold and S its scalar curvature, then the relation ∣W+∣2=S2/6 is well-known. For any almost Kähler 4-manifold with S≥0, this condition forces the Kähler property. A compact almost Kähler 4-manifold is already Kähler if it satisfie…
We study Jacobi structures on the dual bundle A∗ to a vector bundle A such that the Jacobi bracket of linear functions is again linear and the Jacobi bracket of a linear function and the constant function 1 is a basic function. We prove that a Lie algebroid structure on A and a 1-cocycle φ∈Γ(A∗) indu…
A variational principle is proposed for obtaining the Jacobi equations in systems admitting a Lagrangian description. The variational principle gives simultaneously the Lagrange equations of motion and the Jacobi variational equations for the system. The approach can be of help in finding constants of motion in the Jac…
Machine learning helps create accurate models of neutron star postmerger signals.
problem Creating accurate postmerger waveforms for binary neutron stars is challenging due to theoretical uncertainties and limited numerical simulations.
method Used a conditional variational autoencoder (CVAE) to construct postmerger models based on numerical-relativity simulations.
result The CVAE can accurately generate postmerger waveforms and encode the neutron star equation of state.
In this paper we discuss a general framework based on symplectic geometry for the study of second order conditions in constrained variational problems on curves. Using the notion of L-derivatives we construct Jacobi curves, which represent a generalization of Jacobi fields from the classical calculus of variations, but…
In the first part of this paper we outline the constructions and properties of Fedosov star product and Berezin-Toeplitz star product. In the second part we outline the basic ideas and recent developments on Yau-Tian-Donaldson conjecture on the existence of Kähler metrics of constant scalar curvature. In the third part…
Let (M,g) be a Riemannian manifold and G a nondegenerate g-natural metric on its tangent bundle T M . In this paper we establish a relation between the Jacobi operators of (M,g) and that of (T M,G). In the case of a Riemannian surface (M,g), we compute explicitly the spectrum of some Jacobi operators of (TM,G) and give…
We analyze a class of estimators based on convex relaxation for solving high-dimensional matrix decomposition problems. The observations are noisy realizations of a linear transformation X of the sum of an approximately) low rank matrix Θ⋆ with a second matrix Γ⋆ endowed with a complementary …
In this paper, we introduce a new commuting condition between the structure Jacobi operator and symmetric (1,1)-type tensor field T, that is, RξφT=TRξφ, where T=A or T=S for Hopf hypersurfaces in complex hyperbolic two-plane Grassmannians. By using simultaneous diagonalzation for commuting symmetric operators…
In this paper, we have considered a new commuting condition, that is, (Rξφ)S=S(Rξφ) \big(resp. $(\Bar{R}_Nφ) S = S (\Bar{R}_Nφ$)\big) between the restricted Jacobi operator~Rξφ (resp. $\Bar{R}_Nφ$), and the Ricci tensor S for real hypersurfaces M in G2(Cm+2). In terms of this condition we…