#### Filter Results:

- Full text PDF available (8)

#### Publication Year

2002

2015

- This year (0)
- Last 5 years (2)
- Last 10 years (4)

#### Publication Type

#### Co-author

#### Journals and Conferences

#### Key Phrases

Learn More

- William A. Bogley, Jens Harlander
- IJAC
- 2002

We show that for finitely generated groups G with solvable word problem, there is no algorithm to determine whether H 1 (G) is trivial, nor whether H 2 (G) is trivial.

The Σ 3-conjecture for metabelian groups is proved in the split extension case.

- W. A. Bogley, J. Harlander
- 2004

We show that any finitely generated metabelian group can be embedded in a metabelian group of type F 3. More generally, we prove that if n is a positive integer and Q is a finitely generated abelian group, then any finitely generated ZQ-module can be embedded in a module that is n-tame. Combining with standard facts, the F 3 embedding theorem follows from… (More)

- Jens Harlander, Stephan Rosebrock
- 2015

A labeled oriented tree is called injective, if each vertex occurs at most once as an edge label. We show that injective labeled oriented trees are aspherical. The proof uses a new relative asphericity test based on a lemma of Stallings.

Using stably free non-free relation modules we construct an infinite collection of 2–dimensional homotopy types, each of Euler-characteristic one and with trefoil fundamental group. This provides an affirmative answer to a question asked by Berridge and Dunwoody [1]. We also give new examples of exotic relation modules. We show that the relation module… (More)

- W. A. Bogley, J. Harlander
- 2002

We show that any finitely generated metabelian group can be embedded in a metabelian group of type F 3. The proof builds upon work of G. Baumslag [4], who independently with V. R. Remeslennikov [10] proved that any finitely generated metabelian group can be embedded in a finitely presented one. We also rely essentially on the Sigma theory of R. Bieri and R.… (More)

- JENS HARLANDER, ANDREW MISSELDINE, Graham Ellis
- 2011

We construct infinitely many chain homotopically distinct algebraic 2-complexes for the Klein bottle group and give various topological applications. We compare our examples to other examples in the literature and address the question of geometric realizability.

- JENS HARLANDER, CHAO XU, Uwe Kaiser
- 2012

At the center of every crypto system lies a mathematical trapdoor, that is, a computational problem that is easy to perform in one direction (encryption) but difficult to reverse (decryption). The security of the system depends on the difficulty of the reverse computation. The most common problems used are the computation of prime factorizations and the… (More)

- ‹
- 1
- ›