Simplices and Spectra of Graphs

نویسندگان

  • Bojan Mohar
  • Igor Rivin
چکیده

I Let Tn be the set of congruence classes of simplices in Euclidean space E . The set Tn is an open manifold (also a semi-algebraic set) of dimension (n + 1)n/2. Coincidentally, a simplexT ∈ Tn is determined by the (n+1)n/2 lengths of its edges. Furthermore, the square of the volume of T ∈ Tn is a polynomial in the squares of the edgelengths. This polynomial is given by the Cayley-Menger determinant formula: V(T) = (−1) 2n( j!)n detC,

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

THE SPECTRAL DETERMINATION OF THE MULTICONE GRAPHS Kw ▽ C WITH RESPECT TO THEIR SIGNLESS LAPLACIAN SPECTRA

The main aim of this study is to characterize new classes of multicone graphs which are determined by their signless Laplacian spectra. A multicone graph is defined to be the join of a clique and a regular graph. Let C and K w denote the Clebsch graph and a complete graph on w vertices, respectively. In this paper, we show that the multicone graphs K w ▽C are determined by their signless ...

متن کامل

Spectra of Some New Graph Operations and Some New Class of Integral Graphs

In this paper, we define duplication corona, duplication neighborhood corona and duplication edge corona of two graphs. We compute their adjacency spectrum, Laplacian spectrum and signless Laplacian. As an application, our results enable us to construct infinitely many pairs of cospectral graphs and also integral graphs.

متن کامل

COSPECTRALITY MEASURES OF GRAPHS WITH AT MOST SIX VERTICES

Cospectrality of two graphs measures the differences between the ordered spectrum of these graphs in various ways. Actually, the origin of this concept came back to Richard Brualdi's problems that are proposed in cite{braldi}: Let $G_n$ and $G'_n$ be two nonisomorphic simple graphs on $n$ vertices with spectra$$lambda_1 geq lambda_2 geq cdots geq lambda_n ;;;text{and};;; lambda'_1 geq lambda'_2...

متن کامل

INTEGER-MAGIC SPECTRA OF CYCLE RELATED GRAPHS

For any h in N , a graph G = (V, E) is said to be h-magic if there exists a labeling l: E(G) to Z_{h}-{0} such that the induced vertex set labeling l^{+: V(G) to Z_{h}} defined by l^{+}(v)= Summation of l(uv)such that e=uvin in E(G) is a constant map. For a given graph G, the set of all for which G is h-magic is called the integer-magic spectrum of G and is denoted by IM(G). In this paper, the ...

متن کامل

On the Rigidity of Ramanujan Graphs

A graph G is generically [4] rigid in dimension one if and only if it contains a spanning tree, that is, a spanning subgraph assembled by inductively joining 1-simplices along 0-simplices. The analogous property is sufficient but not necessary for the generic rigidity of graphs in higher dimensions, that is, a generically rigid graph in R need not contain a spanning subgraph consisting of n-sim...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Discrete & Computational Geometry

دوره 43  شماره 

صفحات  -

تاریخ انتشار 2010