We investigate the distribution of orbits of a non-elementary discrete hyperbolic subgroup Γ acting on Hn and its geometric boundary ∂∞(H). In particular, we show that if Γ admits a finite Bowen-Margulis-Sullivan measure (for instance, if Γ is geometrically finite), then every Γ-orbit in ∂∞(H) is equidistributed with respect to the Patterson-Sullivan measure supported on the limit set Λ(Γ). The...

A tangent manifold is a pair (M, J) with J a tangent structure (J2 = 0, ker J = im J) on the manifold M . A systematic study of tangent manifolds was done by I. Vaisman in [5]. One denotes by HM any complement of im J := TV . Using the projections h and v on the two terms in the decomposition TM = HM ⊕TV one naturally defines an almost complex structure F on M . Adding to the pair (M, J) a Riem...

To investigate the ultimate bearing capacity and deformation of recycled self-compacting concrete-filled circular steel tubular (RSCCFCST) long columns subjected to axial load, nine specimens with different concrete (RSCC) strength grades slenderness ratios are tested. The experimental results indicate that lateral deflection dominates buckling failure specimens. is enhanced gradually as RSCC g...

There is a canonical exact symplectic structure on the unit tangent bundle of a Riemannian manifold M given by pulling-back the symplectic two form ω and Liouville one form λ from the cotangent bundle T ∗M using the Riemannian metric. The pull-back of λ gives a contact form on level-sets of the length function on TM . The geodesic flow of M is given by the Reeb vectorfield of this contact struc...

Which smooth compact 4-manifolds admit an Einstein metric with non-negative Einstein constant? A complete answer is provided in the special case of 4-manifolds that also happen to admit either a complex structure or a symplectic structure. A Riemannian manifold (M, g) is said to be Einstein if it has constant Ricci curvature, in the sense that the function v −→ r(v, v) on the unit tangent bundl...

1 The Cotangent Complex: General Theory 4 1.1 Stable Envelopes and Tangent Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2 Relative Adjunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3 The Tangent Correspondence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.4 The Relative Cotangent Complex...

The split-radix FFT computes a size-n complex DFT, when n is a large power of 2, using just 4n lgn−6n+8 arithmetic operations on real numbers. This operation count was first announced in 1968, stood unchallenged for more than thirty years, and was widely believed to be best possible. Recently James Van Buskirk posted software demonstrating that the split-radix FFT is not optimal. Van Buskirk’s ...

We describe an algorithm for computing the separating common tangents of two simple polygons using linear time and only constant workspace. A tangent of a polygon is a line touching the polygon such that all of the polygon lies to the same side of the line. A separating common tangent of two polygons is a tangent of both polygons where the polygons are lying on different sides of the tangent. E...

We present a tool that supports the elaboration of behaviour models and scenario-based specification by providing scenario editing, behaviour model synthesis, and model checking for implied scenarios.