Teruaki Kitano And

Twisted Alexander Polynomial and Surjectivity of a Group Homomorphism

If φ : G → G is a surjective homomorphism, we prove that the twisted Alexander polynomial of G is divisible by the twisted Alexander polynomial of G. As an application, we show non-existence of surjective homomorphism between certain knot groups.

Presentation Length and Simon’s Conjecture

Twisted Alexander polynomials and a partial order on the set of prime knots

The twisted Alexander polynomial was introduced by Lin [9] and Wada [18] independently. Lin defined it for a knot by using a regular Seifert surface and Wada defined it for a finitely presentable group by using Fox’s free differential calculus. More generally, Jiang and Wang [3] studied twisted topological invariants for a 3–manifold by using representations of the fundamental group. Following ...

Twisted Alexander polynomials and surjectivity of a group homomorphism

If ϕ : G → G ′ is a surjective homomorphism, we prove that the twisted Alexander polynomial of G is divisible by the twisted Alexander polynomial of G ′. As an application, we show non-existence of surjective homomorphism between certain knot groups.

Squamous Cell Carcinoma Derived from a Skin Flap Used for Reconstruction of the Hypopharynx

Development of a secondary primary cancer in a skin flap is a rare complication. A 70-year-old man underwent partial laryngopharyngectomy, right neck dissection and reconstruction with a radial forearm free flap in 2004. Five years later, an exophytic tumor was found on the hypopharynx reconstructed with the radial forearm free flap. He underwent total laryngopharyngectomy, left neck dissection...