Given a polarization of an even unimodular lattice and integer k ≥ 1, we define a family of unimodular lattices L(M, N, k). Of special interest are certain L(M,N, 3) of rank 72. Their minimum norms lie in {4, 6, 8}. Norms 4 and 6 do occur. Consequently, 6 becomes the highest known minimum norm for rank 72 even unimodular lattices. We discuss how norm 8 might occur for such a L(M,N, 3). We note ...

Recall that a locally compact group G is called unimodular if the left Haar measure on G is equal to the right one. It is proved in this paper that G is unimodular iff it is approximable by finite quasigroups (Latin squares).

In this paper, we construct odd unimodular lattices in dimensions n = 36, 37 having minimum norm 3 and 4s = n − 16, where s is the minimum norm of the shadow. We also construct odd unimodular lattices in dimensions n = 41, 43, 44 having minimum norm 4 and 4s = n− 24.

We explain how one can construct a class of discrete hypergroups which are non-unimodular. They arise as double coset hypergroups induced by the transitive action of a non-unimodular group of permutations on an innnite set. A concrete example is given in terms of the aane group of a homogeneous tree.

All indecomposable unimodular hermitian lattices in dimensions 14 and 15 over the ring of integers in Q( √ −3) are determined. Precisely one lattice in dimension 14 and two lattices in dimension 15 have minimal norm 3. In 1978 W. Feit [10] classified the unimodular hermitian lattices of dimensions up to 12 over the ring Z[ω] of Eisenstein integers, where ω is a primitive third root of unity. Th...

The highest possible minimal norm of a unimodular lattice is determined in dimensions n ≤ 33. There are precisely five odd 32-dimensional lattices with the highest possible minimal norm (compared with more than 8.1020 in dimension 33). Unimodular lattices with no roots exist if and only if n ≥ 23, n 6= 25.

The joint radar and communications (JRC) waveform often has a high range sidelobe, which will degrade the target detection performance of an automotive JRC system. To solve this problem, complementary group (JRC-CWG) design method is proposed in paper by exploiting philosophy sequence. In JRC-CWG, traditional unimodular waveforms, such as binary phase shift keying (BPSK) waveform, are used to p...