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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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48 results for rational functions

Rational neural networks approximate functions more efficiently with less depth.

problem Choosing optimal nonlinear activation functions in neural networks.
method Rational activation functions with optimal bounds and efficiency proofs.
result Rational neural networks approximate smooth functions more efficiently than ReLU networks with exponentially smaller depth.

Neural networks and rational functions efficiently approximate each other. In more detail, it is shown here that for any ReLU network, there exists a rational function of degree O(polylog(1/ε))O(\text{polylog}(1/ε)) which is εε-close, and similarly for any rational function there exists a ReLU network of size $O(\text{polylog}(1/ε…

2017-06-11abs ↗pdf ↗

Study rationality of meromorphic functions between real algebraic sets in the plane.

problem Understanding rationality of meromorphic functions mapping real algebraic sets to complex algebraic sets.
method Using Schwarz reflection functions and theory of meromorphic functions.
result For certain real algebraic sets, meromorphic functions are rational.

In 1973, J. Cheeger and J. Simons raised the following question that still remains open and is known as the Rational Simplex Problem: Given a geodesic simplex in the spherical 3-space so that all of its interior dihedral angles are rational multiples of ππ, is it true that its volume is a rational multiple of the volu…

2013-04-28abs ↗pdf ↗

Study wave functions in complex Chern-Simons theory, finding integrality and rational points.

problem Understanding wave functions in complex Chern-Simons theory.
method Conjecture and prove integrality structure, develop techniques to determine wave functions at rational points.
result Wave functions have integrality structure and can be determined at rational points.

We describe rational knots with any of the possible combinations of the properties (a)chirality, (non-)positivity, (non-)fiberedness, and unknotting number one (or higher), and determine exactly their number for a given number of crossings in terms of their generating functions. We show in particular how Fibonacci numb…

2002-10-11abs ↗pdf ↗

In this paper we prove the following result: if two 2-dimensional 2-homogeneous rational vector fields commute, then either both vector fields can be explicitly integrated to produce rational flows with orbits being lines through the origin, or both flows can be explicitly integrated in terms of algebraic functions. In…

2015-07-27abs ↗pdf ↗

We consider an example of tubes of hypersurfaces in Euclidean space and generalise the tube formula to supercase. By this we assign to a point of the hypersurface in superspace a rational characteristic function. Does this rational function appear when we calculate the zeta-function of an arithmetic variety?

2007-07-13abs ↗pdf ↗

Geometrically describes the linear and quadratic forms for rational links.

problem Predicting generating functions for colored HOMFLY-PT polynomials of rational links.
method Direct geometric description of linear and quadratic forms in terms of configuration spaces.
result Direct geometric description of forms for rational links.

In this paper we investigate the following existence problem for rational functions: for a given collection ΠΠ of partitions of a number nn to define whether there exists a rational function ff of degree nn for which ΠΠ is the branch datum. An important particular case when the answer to this problem is known is t…

2006-11-25abs ↗pdf ↗

In 1985 D.Sullivan had introduced a dictionary between two domains of complex dynamics: iterations of rational functions on the Riemann sphere and Kleinian groups. The latters are discrete subgroups of the group of conformal automorphisms of the Riemann sphere. This dictionary motivated many remarkable results in both …

2006-05-24abs ↗pdf ↗

Graph manifolds' Thurston norms are sums of linear functionals, and every such norm can be realized.

problem Understanding Thurston norms of graph manifolds and their realizability.
method Analyzing the structure of Thurston norms as sums of linear functionals and showing realizability.
result Every Thurston norm of a graph manifold can be expressed as a sum of absolute values of linear functionals with rational coefficients.

Paper introduces rational Gaussian wavelets for efficient signal approximation.

problem Efficiently approximating complex signals with few coefficients.
method Continuous wavelet transform using rational Gaussian wavelets with adjustable parameters.
result Proposed rational Gaussian wavelets provide accurate signal approximations.

In 1999, Rozansky conjectured the existence of a rational presentation of the Kontsevich integral of a knot. Roughly speaking, this rational presentation of the Kontsevich integral would sum formal power series into rational functions with prescribed denominators. Rozansky's conjecture was soon proven by the second aut…

2001-05-03abs ↗pdf ↗

Extends Thurston's combinatorial characterization to all branched coverings of the 2-sphere.

problem Characterizing branched coverings of the 2-sphere.
method Generalizing Thurston's local balancing to all branched coverings.
result Provides a new proof for a theorem concerning real rational functions.

Given an element in the first homology of a rational homology 3-sphere YY, one can consider the minimal rational genus of all knots in this homology class. This defines a function ΘΘ on H1(Y;Z)H_1(Y;\mathbb Z), which was introduced by Turaev as an analogue of Thurston norm. We will give a lower bound for this function usi…

2012-05-31abs ↗pdf ↗

A theory of signatures for odd-dimensional links in rational homology spheres is studied via their generalized Seifert surfaces. The jump functions of signatures are shown invariant under appropriately generalized concordance and a special care is given to accommodate 1-dimensional links with mutual linking. Furthermor…

2001-08-29abs ↗pdf ↗

Bounded rationality, that is, decision-making and planning under resource limitations, is widely regarded as an important open problem in artificial intelligence, reinforcement learning, computational neuroscience and economics. This paper offers a consolidated presentation of a theory of bounded rationality based on i…

2015-12-21abs ↗pdf ↗

Let GG be a finitely generated group with a finite generating set SS. For gGg\in G, let lS(g)l_S(g) be the length of the shortest word over SS representing gg. The growth series of GG with respect to SS is the series A(t)=n=0antnA(t) = \sum_{n=0}^\infty a_n t^n, where ana_n is the number of elements of GG with lS(g)=nl_S(g)=n. If…

2014-01-15abs ↗pdf ↗

Study optimal investment with herd behavior using rational decision decomposition.

problem Optimal investment problem considering herd behavior between two agents.
method Introduce average deviation term, use variational method, rational decision decomposition, investment opinion.
result Quantitative analysis of herd behavior impact on investment decisions.

We study the rational Kontsevich integral of torus knots. We construct explicitely a series of diagrams made of circles joined together in a tree-like fashion and colored by some special rational functions. We show that this series codes exactly the unwheeled rational Kontsevich integral of torus knots, and that it beh…

2004-04-14abs ↗pdf ↗

Characterizes mappings preserving Pythagorean-hodograph curves.

problem Preserving Pythagorean-hodograph curves in various dimensions.
method Proves conformal functions with square rational dilation are PH-preserving.
result Conformal functions with square rational dilation are the only PH-preserving mappings.

The Kontsevich integral of a knot is a powerful invariant which takes values in an algebra of trivalent graphs with legs. Given a Lie algebra, the Kontsevich integral determines an invariant of knots (the so-called colored Jones function) with values in the symmetric algebra of the Lie algebra. Recently A. Kricker and …

2002-01-08abs ↗pdf ↗

Turning the skein relation for HOMFLY into a Fibonacci recurrence, we prove that there are only three rational specializations of HOMFLY polynomial: Alexander-Conway, Jones, and a new one. Using the recurrence relation, we find general and relative expansion formulae and rational generating functions for Alexander-Conw…

2010-03-04abs ↗pdf ↗

We prove that the space M(K(x,y))M(K(x,y)) of R\mathbb R-places of the field K(x,y)K(x,y) of rational functions of two variables with coefficients in a totally Archimedean field KK has covering and integral dimensions $\dim M(K(x,y))=\dim_\IZ M(K(x,y))=2$ and the cohomological dimension dimGM(K(x,y))=1\dim_G M(K(x,y))=1 for any Abelian 2-di…

2011-10-23abs ↗pdf ↗

Study rational homology of moduli space via Morse functions, proving stability phenomena.

problem Homology of Deligne--Mumford compactification of moduli space of stable curves.
method Using a family of Morse functions, specifically the sys_T functions, and exploiting geometric and Morse properties.
result Homology of Deligne--Mumford compactification is supported entirely on the boundary in low degrees, and rational homology is finite generated and stable across all genera and marked points.

Study counts specific surfaces in Montesinos knots with 4 rational tangles.

problem Investigating closed essential surfaces in Montesinos knots with 4 rational tangles.
method Analyzing the number of closed, connected, essential, orientable surfaces of fixed genus in knot complements.
result Exactly 12 genus 2 surfaces and 8φ(g - 1) surfaces of genus greater than 2 are found, independent of knot crossings.