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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.

169,341 papers · 148 categories

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1122 · Feb 201819922001200920182026
19 results for birationality

The paper extends Dunfield's theorem about 3-manifold holonomy maps and volume functions.

problem The birationality of the peripheral holonomy map on character varieties.
method Generalization of Dunfield's rigidity argument using volume functions.
result A conjecture about the volume function on character varieties implies birationality.

After recalling the notion of caustics of plane curves and basic equations, we first show the birationality of the caustic map for a general source point S in the plane. Then we prove more generally a theorem for curves D in the projective space of 3x3 symmetric matrices B. For a general 3x1 vector S the projection to …

2013-04-13abs ↗pdf ↗

Let M be an orientable, cusped hyperbolic 3-manifold of finite volume. We show that the restriction map from a Dehn surgery component in the PSL(2,C)-character variety of M to the character variety of the boundary of M is a birational isomorphism onto its image. This generalises a result by Nathan Dunfield. A key step …

2013-09-24abs ↗pdf ↗

We use a counting argument and surgery theory to show that if DD is a sufficiently general algebraic hypersurface in Cn\Bbb C^n, then any local diffeomorphism F:XCnF:X \to \Bbb C^n of simply connected manifolds which is a dd-sheeted cover away from DD has degree d=1d=1 or d=d=\infty (however all degrees d>1d > 1 are poss…

2007-05-03abs ↗pdf ↗

Proves K-stability and superrigidity of certain singular Fano hypersurfaces.

problem Proving K-stability and superrigidity of singular Fano hypersurfaces.
method Inductive argument using information from lower dimensions and adjunction type results for local volumes of singularities.
result Proves birational superrigidity and K-stability of singular Fano hypersurfaces with specific conditions.

We determine the structure of the Hodge ring, a natural object encoding the Hodge numbers of all compact Kaehler manifolds. As a consequence of this structure, there are no unexpected relations among the Hodge numbers, and no essential differences between the Hodge numbers of smooth complex projective varieties and tho…

2012-02-13abs ↗pdf ↗

Groups of birational transformations with specific properties are conjugate to groups of pseudo-automorphisms.

problem Classifying groups of birational transformations with fixed point properties.
method Importing ideas from geometric group theory, proving conjugacy to groups of pseudo-automorphisms.
result Groups of birational transformations with certain properties are conjugate to groups of pseudo-automorphisms.

The study proves Fano complete intersections' rigidity and stability under certain conditions.

problem The rigidity and stability of Fano complete intersections.
method Birational superrigidity and K-stability criteria.
result Fano complete intersections of index 1 and codimension r in P^(n+r) are birationally superrigid and K-stable for n ≥ 10r.

A classical set of birational invariants of a variety are its spaces of pluricanonical forms and some of their canonically defined subspaces. Each of these vector spaces admits a typical metric structure which is also birationally invariant. These vector spaces so metrized will be referred to as the pseudonormed spaces…

2008-11-18abs ↗pdf ↗

3D hyperbolic manifolds map one-to-one to their boundary character varieties.

problem Mapping 3D hyperbolic manifolds to their boundary character varieties.
method Using Bonahon-Schläfli formula and volume rigidity of discrete co-compact representations.
result Peripheral map is a birational isomorphism with its image.

Study properties of algebraic threefolds with specific singularities.

problem Characterize and classify algebraic threefolds with certain singularities.
method Use topological invariants, rational homology, Poincaré duality, and Lie algebras.
result Relate topological invariants to Lie algebras and representations.

We study holomorphic (n+1)(n+1)-chains EnEn1>...E0E_n\to E_{n-1} \to >... \to E_0 consisting of holomorphic vector bundles over a compact Riemann surface and homomorphisms between them. A notion of stability depending on nn real parameters was introduced in the work of the first two authors and moduli spaces were constructed by t…

2005-12-21abs ↗pdf ↗

The paper proves residual finiteness of certain lattices and constructs surfaces with specific fundamental groups.

problem Residual finiteness of lattices in PU(2,1)~\widetilde{\mathrm{PU}(2,1)} and existence of smooth projective surfaces.
method Proved residual finiteness of certain lattices and constructed surfaces using central extensions.
result First examples of residually finite lattices in PU(2,1)~\widetilde{\mathrm{PU}(2,1)} and construction of surfaces with specific fundamental groups.

Study on mapping classes of real rational surface automorphisms, focusing on reducible maps and pseudo-Anosov maps.

problem Investigating the mapping classes of real rational surface automorphisms and their restrictions.
method Analysis of reducible maps, determination of pseudo-Anosov mapping classes, and comparison with Penner's construction.
result Realized Lehmer's number as the stretch factor of a pseudo-Anosov map on a specific surface.