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 homo-morphism between certain knot groups.
307 arXiv version: fonts, pagination and layout may vary from GTM published version Twisted Alexander polynomials and a partial order on the set of prime knots TERUAKI KITANO MASAAKI SUZUKI We give a survey of some recent papers by the authors and Masaaki Wada [6, 7, 8] relating the twisted Alexander polynomial with a partial order on the set of prime… (More)
We present a computer-oriented method of producing pictures of Bers em-beddings of the Teichmüller space of once-punctured tori. The coordinate plane is chosen in such a way that the accessory parameter is hidden in the relative position of the origin. Our algorithm consists of two steps. To each point in the coordinate plane, we first compute the… (More)
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.
It is not known whether every noncompact hyperbolic 3-manifold of finite volume admits a decomposition into ideal tetrahedra. We give a partial solution to this problem: Let M be a hyperbolic 3-manifold obtained by identifying the faces of n convex ideal polyhedra P 1 ,. .. , Pn. If the faces of P 1 ,. .. , P n−1 are glued to Pn, then M can be decomposed… (More)
The marine gastropod Onchidium has a multiple photoreceptive system consisting of stalk eyes, dorsal eyes, photosensitive neurons, and extraocular dermal photoreceptor cells (DPCs). The DPCs were widespread all over the dorsal mantle and distributed singly or in groups in the dermis, but were not discernible by the naked eye. The DPC was oval in shape and… (More)
We propose a method of extracting scallop areas from gravel seabed images to assess fish resources, and developed an automatic system that measures their quantities, sizes, and states. Scallops feature different colors, fluted patterns and forms. The present study is described our method of extracting these features, and presented the results and its… (More)
—The authors have been working on the support of the fishery industry using the information and communication technology. A water temperature observation network is proposed for supporting aquacultures, and a ubiquitous buoy system developed for this purpose is described. The ubiquitous buoy system was created by leveraging ubiquitous sensing technology… (More)