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48 results for systolic ratio

In this paper we investigate the systolic landscape of translation surfaces for fixed genus and fixed angles of their cone points. We furthermore study how the systoles of a translation surface relate to the systoles of its graph of saddle connections. This allows us to develop an algorithm to compute the systolic rati…

2018-09-27abs ↗pdf ↗

The systolic ratio of a contact form on a closed three-manifold is the quotient of the square of the shortest period of closed Reeb orbits by the contact volume. We show that every co-orientable contact structure on any closed three-manifold is defined by a contact form with arbitrarily large systolic ratio. This shows…

2017-09-05abs ↗pdf ↗

Let (M,g)(M,g) be a closed, oriented, Riemannian manifold of dimension mm. We call a systole a shortest non-contractible loop in (M,g)(M,g) and denote by sys(M,g)sys(M,g) its length. Let SR(M,g)=sys(M,g)mvol(M,g)SR(M,g)=\frac{{sys(M,g)}^m}{vol(M,g)} be the systolic ratio of (M,g)(M,g). Denote by SR(k)SR(k) the supremum of SR(S,g)SR(S,g) among the surfaces of fixe…

2013-11-06abs ↗pdf ↗

The systole of a compact non simply connected Riemannian manifold is the smallest length of a non-contractible closed curve ; the systolic ratio is the quotient (systole)n/volume(\mathrm{systole})^n/\mathrm{volume}. Its supremum on the set of all the riemannian metrics, is known to be finite for a large class of manifolds, including …

2008-04-09abs ↗pdf ↗

We find an upper bound for the entropy of a systolically extremal surface, in terms of its systole. We combine the upper bound with A. Katok's lower bound in terms of the volume, to obtain a simpler alternative proof of M. Gromov's asymptotic estimate for the optimal systolic ratio of surfaces of large genus. Furthermo…

2004-10-13abs ↗pdf ↗

A compact manifold is called Bieberbach if it carries a flat Riemannian metric. Bieberbach manifolds are aspherical, therefore the supremum of their systolic ratio, over the set of Riemannian metrics, is finite by a fundamental result of M. Gromov. We study the optimal systolic ratio of compact of 33-dimensional orien…

2009-12-19abs ↗pdf ↗

We study optimal curvature-free inequalities of the type discovered by C. Loewner and M. Gromov, using a generalisation of the Wirtinger inequality for the comass. Using a model for the classifying space BS^3 built inductively out of BS^1, we prove that the symmetric metrics of certain two-point homogeneous manifolds t…

2006-08-01abs ↗pdf ↗

We study the systolic area (defined as the ratio of the area over the square of the systole) of the 2-sphere endowed with a smooth riemannian metric as a function of this metric. This function, bounded from below by a positive constant over the space of metrics, have the standard metric g_0g\_0 for critic point, althoug…

2006-01-12abs ↗pdf ↗

We prove an optimal systolic inequality for CAT(0) metrics on a genus~2 surface. We use a Voronoi cell technique, introduced by C.~Bavard in the hyperbolic context. The equality is saturated by a flat singular metric in the conformal class defined by the smooth completion of the curve y^2=x^5-x. Thus, among all CAT(0) …

2005-01-02abs ↗pdf ↗

Let αα be a contact form on a connected closed three-manifold ΣΣ. The systolic ratio of αα is defined as ρsys(α):=1Vol(α)Tmin(α)2ρ_{\mathrm{sys}}(α):=\tfrac{1}{\mathrm{Vol}(α)}T_{\min}(α)^2, where Tmin(α)T_{\min}(α) and Vol(α)\mathrm{Vol}(α) denote the minimal period of periodic Reeb orbits and the contact volume. The form αα is said to be Zoll …

2019-02-04abs ↗pdf ↗

We are interested in the maximum value achieved by the systole function over all complete finite area hyperbolic surfaces of a given signature (g,n)(g,n). This maximum is shown to be strictly increasing in terms of the number of cusps for small values of nn. We also show that this function is greater than a function that…

2012-01-17abs ↗pdf ↗

Let S be a closed orientable surface of genus at least 2 and let G be a semisimple real algebraic group of non-compact type. We consider a class of representations from the fundamental group of S to G called positively ratioed representations. These are Anosov representations with the additional condition that certain …

2016-09-05abs ↗pdf ↗

If a contact form on a (2n+1)-dimensional closed contact manifold admits closed Reeb orbits, then its systolic ration is defined to be the quotient of (n+1)th power of the shortest period of Reeb orbits by the contact volume. We prove that every co-orientable contact structure on any closed contact manifold admits a co…

2018-06-06abs ↗pdf ↗

We give asymptotic bounds for the optimal Lipschitz constants for the systole map from the Teichmuller space to the curve complex. We give similar results to those known for closed surfaces in the cases when the genus is fixed or the ratio of genus and punctures is a rational number.

2014-09-09abs ↗pdf ↗

The study connects contact forms and Ruelle invariant in convex domains.

problem Understanding the relationship between contact forms and Ruelle invariant in convex domains.
method Using the extrinsic curvature and Ruelle invariant, the authors prove bounds and construct counterexamples.
result First examples of dynamically convex contact 3-spheres not strictly contactomorphic to convex boundaries.

The systolic ratio of a contact form αα on the three-sphere is the quantity \[ ρ_{\mathrm{sys}}(α) = \frac{T_{\min}(α)^2}{\mathrm{vol}(S^3,α\wedge dα)}, \] where Tmin(α)T_{\min}(α) is the minimal period of closed Reeb orbits on (S3,α)(S^3,α). A Zoll contact form is a contact form such that all the orbits of the corresponding R…

2015-04-20abs ↗pdf ↗

A new systolic inequality for mod 2 systoles is established.

problem Bounding the product of mod 2 systoles in Riemannian manifolds.
method Analyzing the product of systoles of dimensions 1 and n-1 in closed manifolds with bounded local geometry.
result A systolic inequality is derived for the product of mod 2 systoles, showing a power-law relationship with volume.

We investigate the geometry of π1π_1-injective surfaces in closed hyperbolic 3-manifolds. First we prove that for any e>0e>0, if the manifold MM has sufficiently large systole $\sys_1(M)$, the genus of any such surface in MM is bounded below by $\exp((1/2-e)\sys_1(M))$. Using this result we show, in particular, that f…

2012-05-23abs ↗pdf ↗

We prove a new systolic volume lower bound for non-orientable n-manifolds, involving the stable 1-systole and the codimension 1 systole with coefficients in Z_2. As an application, we prove that Lusternik-Schnirelmann category and systolic category agree for non-orientable closed manifolds of dimension 3, extending our…

2005-04-01abs ↗pdf ↗

In this paper, we prove that the systolic volume of a closed aspherical 3-manifold is bounded below in terms of complexity. Systolic volume is defined as the optimal constant in a systolic inequality. Babenko showed that the systolic volume is a homotopy invariant. Moreover, Gromov proved that the systolic volume depen…

2015-09-25abs ↗pdf ↗

Geometrically, spherical 3-manifolds emerge from flat SU(2)-bundles over hyperbolic surfaces.

problem Realizing spherical 3-manifolds from flat SU(2)-bundles over hyperbolic surfaces.
method Using Gromov-Hausdorff convergence and systole maximization over moduli spaces.
result Homogeneous spherical 3-manifolds can be realized as limits of metric spaces of flat SU(2)-bundles.

New finding links hyperbolic manifold systolic volume to triangulation complexity.

problem Understanding the relationship between systolic volume and triangulation complexity in hyperbolic manifolds.
method Proof based on Jørgensen and Thurston's theorem of hyperbolic volume.
result Systolic volume of hyperbolic manifolds is related to triangulation complexity.

Following an idea of Dadok, Harvey and Lawson, we apply the triality property of SO(8) to study the comass of certain self-dual 4-forms on R^8. In particular, we prove that the Cayley 4-form has comass 1 and that any self-dual 4-form realizing the maximal Wirtinger ratio is SO(8)-conjugate to the Cayley 4-form. We also…

2008-01-01abs ↗pdf ↗

For all systolic groups we construct boundaries which are EZ--structures. This implies the Novikov conjecture for torsion--free systolic groups. The boundary is constructed via a system of distinguished geodesics in a systolic complex, which we prove to have coarsely similar properties to geodesics in CAT(0) spaces.

2008-08-17abs ↗pdf ↗