6,483 research outputs found
On the algebra of cornered Floer homology
Bordered Floer homology associates to a parametrized oriented surface a
certain differential graded algebra. We study the properties of this algebra
under splittings of the surface. To the circle we associate a differential
graded 2-algebra, the nilCoxeter sequential 2-algebra, and to a surface with
connected boundary an algebra-module over this 2-algebra, such that a natural
gluing property is satisfied. Moreover, with a view toward the structure of a
potential Floer homology theory of 3-manifolds with codimension-two corners, we
present a decomposition theorem for the Floer complex of a planar grid diagram,
with respect to vertical and horizontal slicing.Comment: a few minor revision
The balanced tensor product of module categories
The balanced tensor product M (x)_A N of two modules over an algebra A is the
vector space corepresenting A-balanced bilinear maps out of the product M x N.
The balanced tensor product M [x]_C N of two module categories over a monoidal
linear category C is the linear category corepresenting C-balanced right-exact
bilinear functors out of the product category M x N. We show that the balanced
tensor product can be realized as a category of bimodule objects in C, provided
the monoidal linear category is finite and rigid.Comment: 19 pages; v3 is author-final versio
Topological modular forms and conformal nets
We describe the role conformal nets, a mathematical model for conformal field
theory, could play in a geometric definition of the generalized cohomology
theory TMF of topological modular forms. Inspired by work of Segal and
Stolz-Teichner, we speculate that bundles of boundary conditions for the net of
free fermions will be the basic underlying objects representing TMF-cohomology
classes. String structures, which are the fundamental orientations for
TMF-cohomology, can be encoded by defects between free fermions, and we
construct the bundle of fermionic boundary conditions for the TMF-Euler class
of a string vector bundle. We conjecture that the free fermion net exhibits an
algebraic periodicity corresponding to the 576-fold cohomological periodicity
of TMF; using a homotopy-theoretic invariant of invertible conformal nets, we
establish a lower bound of 24 on this periodicity of the free fermions
Conformal nets I: coordinate-free nets
We describe a coordinate-free perspective on conformal nets, as functors from
intervals to von Neumann algebras. We discuss an operation of fusion of
intervals and observe that a conformal net takes a fused interval to the fiber
product of von Neumann algebras. Though coordinate-free nets do not a priori
have vacuum sectors, we show that there is a vacuum sector canonically
associated to any circle equipped with a conformal structure. This is the first
in a series of papers constructing a 3-category of conformal nets, defects,
sectors, and intertwiners.Comment: Updated to published versio
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