Search arXiv⌕ Search

arXiv · math/0405010

Normalized Ricci flow on Riemann surfaces and determinants of Laplacian

Abstract

In this note we give a simple proof of the fact that the determinant of Laplace operator in smooth metric over compact Riemann surfaces of arbitrary genus $g$ monotonously grows under the normalized Ricci flow. Together with results of Hamilton that under the action of the normalized Ricci flow the smooth metric tends asymptotically to metric of constant curvature for $g\geq 1$, this leads to a simple proof of Osgood-Phillips-Sarnak theorem stating that that within the class of smooth metrics with fixed conformal class and fixed volume the determinant of Laplace operator is maximal on metric of constant curvatute.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A. Kokotov, D. Korotkin. 2009-01-10. Normalized Ricci flow on Riemann surfaces and determinants of Laplacian. https://doi.org/10.1007/s11005-005-1451-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Weighted eigenvalues of Dirac operators: complete continuity and comparison

We give a min-max characterization of all of the weighted Dirac eigenvalues, and show that the weighted eigenvalues and eigenspaces of Dirac operators are continuous with respect to weak $L^p$ convergence of the weight, for any $p>n$. Moreover, we establish a comparison result for such weighted eigenvalue problems including the case of nontrivial harmonic spinors.

math.SP↗

Neighbourhood second Zagreb matrix of graphs: spectral radius bounds and extremal graphs

Let $G$ be a connected graph on at least two vertices, and let $δ(i)$ be the sum of the degrees of the neighbours of a vertex $i$. The \emph{neighbourhood second Zagreb matrix} $\NF(G)$ has $(i,j)$-entry $δ(i)δ(j)$ if $i\sim j$ and $0$ otherwise; its spectral radius is denoted by $\rNF(G)$. We prove that $\rNF(G)\geρ(G)^{5}$, where $ρ(G)$ is the adjacency spectral radius, with equality if and only if $G$ is regular or bipartite semiregular, and we use this to show that the same graphs are exactly the extremal graphs of a Berman--Zhang--type upper bound. We sharpen the estimates $\demin^{2}ρ(G)\le\rNF(G)\le\demax^{2}ρ(G)$ by means of the extreme edge weights of $\NF(G)$, give sharp upper bounds in terms of the maximum degree $\dmax$, the maximum neighbourhood degree sum $\demax$, the size $m$ and the clique number $ω(G)$, and determine the extremal graphs for bipartite graphs and trees. For every connected unicyclic graph $G$ of order $n\ge3$ we prove $32=\rNF(C_n)\le\rNF(G)\le\rNF(\Sp n)$, where $\Sp n$ is the triangle with $n-3$ pendant edges at one vertex, with equality only for $C_n$ and only for $\Sp n$, respectively. Finally, we give bounds in terms of the first Zagreb index and for the neighbourhood second Zagreb energy; for lower energy bounds, the extremal graphs are described completely.

math.SP↗

On isospectral potentials on periodic discrete graphs

We consider discrete Schrödinger operators with periodic (possibly complex valued) potentials $Q$ on periodic graphs. Using a system of spectral invariants obtained in \cite{S26}, we investigate the sets of isospectral potentials on periodic graphs. In particular, we show that the Floquet spectrum of the Schrödinger operators on the hexagonal lattice and on the Kagome lattice generically (with respect to perturbations of $Q$) determines the potential $Q$ uniquely up to the obvious symmetries (translations and rotations) in the periodic graph.

math.SP↗