On the Iwasawa invariants for links and Kida's formula

Analogues of Iwasawa invariants in the context of 3-dimensional topology have been studied by M.~Morishita and others. In this paper, following the dictionary of arithmetic topology, we formulate an analogue of Kida's formula on $\lambda$-invariants in a $p$-extension of $\mathbb{Z}_p$-fields for 3-manifolds. The proof is given in a parallel manner to Iwasawa's second proof, with use of $p$-adic representations of a finite group. In the course of our arguments, we introduce the notion of a branched $\mathbb{Z}_p$-cover as an inverse system of cyclic branched $p$-covers of 3-manifolds, generalize the Iwasawa type formula, and compute the Tate cohomology of 2-cycles explicitly.Comment: 26 pages, 1 figure; Minor modification

Classical and quantum behavior of the integrated density of states for a randomly perturbed lattice

The asymptotic behavior of the integrated density of states for a randomly perturbed lattice at the infimum of the spectrum is investigated. The leading term is determined when the decay of the single site potential is slow. The leading term depends only on the classical effect from the scalar potential. To the contrary, the quantum effect appears when the decay of the single site potential is fast. The corresponding leading term is estimated and the leading order is determined. In the multidimensional cases, the leading order varies in different ways from the known results in the Poisson case. The same problem is considered for the negative potential. These estimates are applied to investigate the long time asymptotics of Wiener integrals associated with the random potentials.Comment: 27 page

Innovation in Linked and Non-linked Firms: Effects of Variety of Linkages in East Asia

This paper proposes a new mechanism linking innovation and network in developing economies to detect explicit production and information linkages and investigates the testable implications of these linkages using survey data gathered from manufacturing firms in Indonesia, Thailand, the Philippines, and Vietnam. In-house R&D activities, internal resources, and linkages with local firms and foreign firms play a role in reducing the costs of product and process innovation and search costs for finding new suppliers and customers. We found that firms with more varieties of information linkages achieve more types of innovations. Complementarities between internal and external sources of knowledge are also found.- innovation, linkages, sources of knowledge, dissimilarity, complementarities

The Impacts of Face-to-face and Frequent Interactions on Innovation: Upstream-Downstream Relations

This paper proposes a new mechanism linking innovation and networks in developing economies to identify explicit production and information linkages and investigates the testable hypotheses of these linkages using survey data gathered from manufacturing firms in East Asia: Indonesia, Thailand, the Philippines, and Vietnam. We found that firms that dispatched engineers to customers achieved more innovations than firms that did not. Just-in-time relationship is effective for dealing with process innovation. We found that such strong complementarities are not effective for product innovation. These findings support the hypothesis that face-to-face communication and strong complementarities among buyer-seller networks have different roles in product and process innovation.

Linked versus Non-linked Firms in Innovation: The Effects of Economies of Network in Agglomeration in East Asia

This paper proposes a new mechanism linking innovation and network in developing economies to detect explicit production and information linkages and investigates the testable implications of these linkages using survey data gathered from manufacturing firms in East Asia. We found that firms with more information linkages tend to innovate more, have a higher probability of introducing new goods, introducing new goods to new markets using new technologies, and finding new partners located in remote areas. We also found that firms that dispatched engineers to customers achieved more innovations than firms that did not. These findings support the hypothesis that production linkages and faceâ€toâ€face communication encourage product and process innovation.Southeast Asia, East Asia, Technological innovations, Network, Communication, Business enterprises, Engineer Mobility, Innovation, Linkages

Impacts of Incoming Knowledge on Product Innovation: Technology Transfer in Auto-related Industries in Developing Economies

This paper studies two questions on the role of networked sources of knowledge influential to product innovation. First: What is the extent of technology transferred through vertical linkages and public-private alliances, including university-industry linkages, in the phase of product improvement and development? Second: What types of knowledge are transferred from external technology sources? In a sample of ASEAN firms’ self-reported partner data restricted to automotive related industries, we found that direct linkages with MNC customers in foreign countries resulted in a lower propensity of product innovation. Indeed, incoming knowledge from MNC customers relating to the management of quality of existing products especially explained the lower propensity of product innovation. We also found that production linkages with MNC suppliers in foreign countries resulted in a higher propensity of product innovation. Incoming knowledge from MNC suppliers about quality controls explained a lower propensity of product innovation. These findings empirically indicate that networked sources of knowledge have a significant influence trade-off between maintaining existing operations and developing new products. The impacts of public-private alliances on innovation are sizable compared with the impacts of vertical linkages. Public-private alliances and vertical linkages offer knowledge with different effects on product innovation.

Transport modal choice by multinational firms : firm-level evidence from Southeast Asia

We examine transport modal decision by multinational firms to shed light on the role of freight logistics in multinational activity. Using a firm-level survey in Southeast Asia, we show that foreign ownership has a significantly positive and quantitatively large impact on the likelihood that air/sea transportation is chosen relative to truck shipping. This result is robust to the shipping distance, cross-border freight, and transport infrastructure. Both foreign-owned exporters and importers also tend to use air/sea transportation. Thus, our analysis presents a new distinction between multinational and domestic firms in their decision over transport modes.International business enterprises, Industrial management, Transportation, Costs, Southeast Asia, Transport mode, Logistics, Multinational firms, Multinomial logit

On the universal deformations for SL_2-representations of knot groups

Based on the analogies between knot theory and number theory, we study a deformation theory for SL_2-representations of knot groups, following after Mazur's deformation theory of Galois representations. Firstly, by employing the pseudo-SL_2-representations, we prove the existence of the universal deformation of a given SL_2-representation of a finitely generated group Pi over a field whose characteristic is not 2. We then show its connection with the character scheme for SL_2-representations of Pi when k is an algebraically closed field. We investigate examples concerning Riley representations of 2-bridge knot groups and give explicit forms of the universal deformations. Finally we discuss the universal deformation of the holonomy representation of a hyperbolic knot group in connection with Thurston's theory on deformations of hyperbolic structures.Comment: 25 pages, to appear in Tohoku Math. J; corrected typo