Hiroshi Ohta

The Memoirs of the AMS is devoted to the publication of new research in all areas of pure and applied mathematics. The Memoirs is designed particularly to publish long papers of groups of cognate papers in book form, and is under the supervision of the Editorial Committee of the AMS journal Transactions of the American Mathematical Society. All papers are peer-reviewed.

The package of Gromov’s pseudo-holomorphic curves is a major tool in global symplectic geometry and its applications, including mirror symmetry and Hamiltonian dynamics. The Kuranishi structure was introduced by two of the authors of the present volume in the mid-1990s to apply this machinery on general symplectic manifolds without assuming any specific restrictions. It was further amplified by this book’s authors in their monograph Lagrangian Intersection Floer Theory and in many other publications of theirs and others. Answering popular demand, the authors now present the current book, in which they provide a detailed, self-contained explanation of the theory of Kuranishi structures.Part I discusses the theory on a single space equipped with Kuranishi structure, called a K-space, and its relevant basic package. First, the definition of a K-space and maps to the standard manifold are provided. Definitions are given for fiber products, differentialforms, partitions of unity, and the notion of CF-perturbations on the K-space. Then, using CF-perturbations, the authors define the integration on K-space and the push-forward of differential forms, and generalize Stokes' formula and Fubini's theorem in this framework. Also, “virtual fundamental class” is defined, and its cobordism invariance is proved.Part II discusses the (compatible) system of K-spaces and the process of going from “geometry” to “homological algebra”. Thorough explanations of the extension of given perturbations on the boundary to the interior are presented. Also explained is the process of taking the “homotopy limit” needed to handle a system of infinitely many moduli spaces. Having in mind the future application of these chain level constructions beyond those already known, an axiomatic approach is taken by listing the properties of the system of the relevant moduli spaces and then a self-contained account of the construction of the associated algebraic structures is given. This axiomatic approach makes the exposition contained here independent of previously published construction of relevant structures.

The package of Gromov’s pseudo-holomorphic curves is a major tool in global symplectic geometry and its applications, including mirror symmetry and Hamiltonian dynamics. The Kuranishi structure was introduced by two of the authors of the present volume in the mid-1990s to apply this machinery on general symplectic manifolds without assuming any specific restrictions. It was further amplified by this book’s authors in their monograph Lagrangian Intersection Floer Theory and in many other publications of theirs and others. Answering popular demand, the authors now present the current book, in which they provide a detailed, self-contained explanation of the theory of Kuranishi structures.Part I discusses the theory on a single space equipped with Kuranishi structure, called a K-space, and its relevant basic package. First, the definition of a K-space and maps to the standard manifold are provided. Definitions are given for fiber products, differentialforms, partitions of unity, and the notion of CF-perturbations on the K-space. Then, using CF-perturbations, the authors define the integration on K-space and the push-forward of differential forms, and generalize Stokes' formula and Fubini's theorem in this framework. Also, “virtual fundamental class” is defined, and its cobordism invariance is proved.Part II discusses the (compatible) system of K-spaces and the process of going from “geometry” to “homological algebra”. Thorough explanations of the extension of given perturbations on the boundary to the interior are presented. Also explained is the process of taking the “homotopy limit” needed to handle a system of infinitely many moduli spaces. Having in mind the future application of these chain level constructions beyond those already known, an axiomatic approach is taken by listing the properties of the system of the relevant moduli spaces and then a self-contained account of the construction of the associated algebraic structures is given. This axiomatic approach makes the exposition contained here independent of previously published construction of relevant structures.

In this paper the authors first develop various enhancements of the theory of spectral invariants of Hamiltonian Floer homology and of Entov-Polterovich theory of spectral symplectic quasi-states and quasi-morphisms by incorporating bulk deformations, i.e., deformations by ambient cycles of symplectic manifolds, of the Floer homology and quantum cohomology. Essentially the same kind of construction is independently carried out by Usher in a slightly less general context. Then the authors explore various applications of these enhancements to the symplectic topology, especially new construction of symplectic quasi-states, quasi-morphisms and new Lagrangian intersection results on toric and non-toric manifolds.The most novel part of this paper is its use of open-closed Gromov-Witten-Floer theory and its variant involving closed orbits of periodic Hamiltonian system to connect spectral invariants (with bulk deformation), symplectic quasi-states, quasi-morphism to the Lagrangian Floer theory (with bulk deformation).The authors use this open-closed Gromov-Witten-Floer theory to produce new examples. Using the calculation of Lagrangian Floer cohomology with bulk, they produce examples of compact symplectic manifolds $(M,\omega)$ which admits uncountably many independent quasi-morphisms $\widetilde{{\rm Ham}}(M,\omega) \to {\mathbb{R}}$. They also obtain a new intersection result for the Lagrangian submanifold in $S^2 \times S^2$.

This is a Festschrift to honour Professor Melvin Greenhut who has long toiled on spatial economics. The book accordingly focuses on a single question: in what sense 'economic space' matters in economic theory. Space in economics is an elusive concept, apparently separating and embracing economic agents at the same time. This is why adding it to already overly complicated economic agents at the same time. This is why adding it to already overly complicated economic models may not necessarily help economics to become sufficiently realistic. In this book, leading scholars of international stature try to find ways of introducing space in economic theory which will make it simpler and more realistic, analysing theoretical and historical issues of contemporary relevance, such as land use, congestion and public goods, location theory and spatial competition.

This is a Festschrift to honour Professor Melvin Greenhut who has long toiled on spatial economics. The book accordingly focuses on a single question: in what sense 'economic space' matters in economic theory. Space in economics is an elusive concept, apparently separating and embracing economic agents at the same time. This is why adding it to already overly complicated economic agents at the same time. This is why adding it to already overly complicated economic models may not necessarily help economics to become sufficiently realistic. In this book, leading scholars of international stature try to find ways of introducing space in economic theory which will make it simpler and more realistic, analysing theoretical and historical issues of contemporary relevance, such as land use, congestion and public goods, location theory and spatial competition.

Economic space is the distance that separates economic agents such as manufacturers and consumers. Distance naturally imposes costs on the economic agents, but it has long been a neglected element in orthodox economic theory, one thought to complicate the issue unnecessarily. However, the theoretical implications of assuming away spatial elements may be especially significant for pricing practices and hence for competition. This volume shows why and in what ways the concept of economic space is vital and thus needed to reform orthodox price theory. It negates the classical paradigm of perfect competition and calls for a spatial price theory of imperfect competition. Among Hiroshi Ohta's findings in spatial microeconomic theory are that unlimited entry of new firms into the market may not lower consumer prices and that increased labor productivity in a spatial economy may actually lower real wages. Researchers and students of economic geography and regional science and economics will find the author's careful analysis, equations, and illustrations valuable in understanding a decade of advances in spatial price theory and in exploring new theories of competition.