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The aim of this paper is to describe the equivariant and ordinary Grothendieck ring and the equivariant and ordinary topological K$K$‐ring of flag Bott manifolds of the general Lie type. This will generalize the results on the equivariant and ordinary cohomology of flag Bott manifolds of the general Lie type due to Kaji, Kuroki, Lee, and Suh. [ABSTRACT FROM AUTHOR]

Let p be an odd prime and let ρ : ℤ / p → GL n ⁡ (ℤ) be an action of ℤ / p on a lattice and let Γ := ℤ n ⋊ ρ ℤ / p be the corresponding semidirect product. The torus bundle M := T ρ n × ℤ / p S ℓ over the lens space S ℓ / ℤ / p has fundamental group Γ. When ℤ / p fixes only the origin of ℤ n , Davis and Lück (2021) compute the L-groups L m 〈 j 〉 ⁢ (ℤ ⁢ [ Γ ]) and the structure set 풮 geo , s ⁢ (M) . In this paper, we extend these computations to all actions of ℤ / p on ℤ n . In particular, we compute L m 〈 j 〉 ⁢ (ℤ ⁢ [ Γ ]) and 풮 geo , s ⁢ (M) in a case where E ¯ ⁢ Γ has a non-discrete singular set. [ABSTRACT FROM AUTHOR]

We give a Chevalley formula for an arbitrary weight for the torus-equivariant K-group of semi-infinite flag manifolds, which is expressed in terms of the quantum alcove model. As an application, we prove the Chevalley formula for an anti-dominant fundamental weight for the (small) torus-equivariant quantum K-theory Q K T (G / B) of a (finite-dimensional) flag manifold G/B; this has been a longstanding conjecture about the multiplicative structure of Q K T (G / B) . In type A n - 1 , we prove that the so-called quantum Grothendieck polynomials indeed represent (opposite) Schubert classes in the (non-equivariant) quantum K-theory Q K (S L n / B) ; we also obtain very explicit information about the coefficients in the respective Chevalley formula. [ABSTRACT FROM AUTHOR]

Let K be a finite extension of the p -adic numbers Q p with ring of integers O K and residue field κ. Let X a regular scheme, proper, flat, and geometrically irreducible over O K of dimension d , and X K its generic fiber. We show, under some assumptions on X , that there is a reciprocity isomorphism of locally compact groups H a r 2 d − 1 (X K , Z (d)) ≃ π 1 a b (X K) W from the cohomology theory defined in [10] to an integral model π 1 a b (X K) W of the abelianized fundamental group π 1 a b (X K). After removing the contribution from the base field, the map becomes an isomorphism of finitely generated abelian groups. The key ingredient is the duality result in [10]. [ABSTRACT FROM AUTHOR]

In this note we confirm the conjecture of Calegari, Garoufalidis and Zagier in [3] that R ζ = c ζ 2 where R ζ is their map on K 3 defined using the cyclic quantum dilogarithm and c ζ is the Chern class map on K 3. [ABSTRACT FROM AUTHOR]

We introduce and investigate some examples of C ∗ -algebras which are related to multiplication maps in the ring of p-adic integers. We find ideals within these algebras and use the corresponding short exact sequences to compute the K-theory. [ABSTRACT FROM AUTHOR]

Frieze groups are discrete subgroups of the full group of isometries of a flat strip. We investigate here the dynamics of specific architected materials generated by acting with a frieze group on a collection of self-coupling seed resonators. We demonstrate that, under unrestricted reconfigurations of the internal structures of the seed resonators, the dynamical matrices of the materials generate the full self-adjoint sector of the stabilized group C*-algebra of the frieze group. As a consequence, in applications where the positions, orientations and internal structures of the seed resonators are adiabatically modified, the spectral bands of the dynamical matrices carry a complete set of topological invariants that are fully accounted by the K-theory of the mentioned algebra. By resolving the generators of the K-theory, we produce the model dynamical matrices that carry the elementary topological charges, which we implement with systems of plate resonators to showcase several applications in spectral engineering. The paper is written in an expository style. [ABSTRACT FROM AUTHOR]

In this paper, extending the results in Fok (Proc Am Math Soc 145:2799–2813, 2017), we compute Adams operations on the twisted K-theory of connected, simply-connected and simple compact Lie groups G, in both equivariant and nonequivariant settings. [ABSTRACT FROM AUTHOR]

In the early 1940s, P. A. Smith showed that if a finite p-group G acts on a finite dimensional complex X that is mod p acyclic, then its space of fixed points, XG, will also be mod p acyclic. In their recent study of the Balmer spectrum of equivariant stable homotopy theory, Balmer and Sanders were led to study a question that can be shown to be equivalent to the following: if a G-space X is a equivariant homotopy retract of the p-localization of a based finite G-C.W. complex, given H < G and n, what is the smallest r such that if XH is acyclic in the (n+r)th Morava K-theory, then XG must be acyclic in the nth Morava K-theory? Barthel et. al. then answered this when G is abelian, by finding general lower and upper bounds for these "blue shift" numbers which agree in the abelian case. In our paper, we first prove that these potential chromatic versions of Smith's theorem are equiv- alent to chromatic versions of a 1952 theorem of E. E. Floyd, which replaces acyclicity by bounds on dimensions of mod p homology, and thus applies to all finite dimensional G-spaces. This unlocks new techniques and applications in chromatic fixed point theory. Applied to the problem of understanding blue shift numbers, we are able to use classic constructions and representation theory to search for lower bounds. We give a simple new proof of the known lower bound theorem, and then get the first results about nonabelian 2-groups that do not follow from previously known results. In particular, we are able to determine all blue shift numbers for extraspecial 2-groups. Applied in ways analogous to Smith's original applications, we prove new fixed point theorems for K(n)*-homology disks and spheres. Finally, our methods offer a new way of using equivariant results to show the collapsing of certain Atiyah-Hirzebruch spectral sequences in certain cases. Our criterion appears to apply to the calculation of all 2-primary Morava K-theories of all real Grassmanians. [ABSTRACT FROM AUTHOR]

We develop tools to analyze and compare the Brauer groups of spectra such as periodic complex and real K$K$‐theory and topological modular forms, as well as the derived moduli stack of elliptic curves. In particular, we prove that the Brauer group of TMF$\mathrm{TMF}$ is isomorphic to the Brauer group of the derived moduli stack of elliptic curves. Our main computational focus is on the subgroup of the Brauer group consisting of elements trivialized by some étale extension, which we call the local Brauer group. Essential information about this group can be accessed by a thorough understanding of the Picard sheaf and its cohomology. We deduce enough information about the Picard sheaf of TMF$\mathrm{TMF}$ and the (derived) moduli stack of elliptic curves to determine the structure of their local Brauer groups away from the prime 2. At 2, we show that they are both infinitely generated and agree up to a potential error term that is a finite 2‐torsion group. [ABSTRACT FROM AUTHOR]

We construct a natural generalization of the Grothendieck group K0 to the case of possibly unpointed categories admitting pushouts by using the concept of heaps recently introduced by Brezinzki. In case of a monoidal category, the defined K0 is shown to be a truss. It is shown that the construction generalizes the classical K0 of an abelian category as the group retract along the isomorphism class of the zero object. We finish by applying this construction to construct the integers with addition and multiplication as the decategorification of finite sets and show that in this K0(Top̲) one can identify a CW-complex with the iterated product of its cells. [ABSTRACT FROM AUTHOR]

We derive cancellation-free Chevalley-type multiplication formulas for the T -equivariant quantum K -theory ring of Grassmannians of type A and C , and also those of two-step flag manifolds of type A. They are obtained based on the uniform Chevalley formula in the T -equivariant quantum K -theory ring of arbitrary flag manifolds G / B , which was derived earlier in terms of the quantum alcove model, by the last three authors. [ABSTRACT FROM AUTHOR]

An error in the original paper is identified and corrected. The |$\textrm {C}^{\ast }$| -algebras with approximately inner flip, which satisfy the UCT, are identified (and turn out to be fewer than what is claimed in the original paper). The action of the flip map on K-theory turns out to be more subtle, involving a minus sign in certain components. To this end, we introduce new geometric resolutions for |$\textrm {C}^{\ast }$| -algebras, which do not involve index shifts in K-theory and thus allow for a more explicit description of the quotient map in the Künneth formula for tensor products. [ABSTRACT FROM AUTHOR]

We find new examples of complex surfaces with countably many non-isomorphic algebraic structures. Here is one such example: take an elliptic curve |$E$| in |$\mathbb P^{2}$| and blow up nine general points on |$E$|⁠. Then the complement |$M$| of the strict transform of |$E$| in the blow-up has countably many algebraic structures. Moreover, each algebraic structure comes from an embedding of |$M$| into a blow-up of |$\mathbb P^{2}$| in nine points lying on an elliptic curve |$F\not \simeq E$|⁠. We classify algebraic structures on |$M$| using a Hopf transform : a way of constructing a new surface by cutting out an elliptic curve and pasting a different one. Next, we introduce the notion of an analytic K-theory of varieties. Manipulations with the example above lead us to prove that classes of all elliptic curves in this K-theory coincide. To put in another way, all motivic measures on complex algebraic varieties that take equal values on biholomorphic varieties do not distinguish elliptic curves. [ABSTRACT FROM AUTHOR]

The aim of this paper is to describe the topological K-ring in terms of generators and relations of a flag Bott manifold. We apply our results to give a presentation for the topological K-ring, and hence the Grothendieck ring of algebraic vector bundles over flag Bott–Samelson varieties. [ABSTRACT FROM AUTHOR]

We analyze topological invariants, in particular Z 2 invariants, which characterize time reversal invariant topological insulators, in the framework of index theory and K-theory. After giving a careful study of the underlying geometry and K-theory, we formalize topological invariants as elements of KR theory. To be precise, the strong topological invariants lie in the higher KR groups of spheres; K R ̃ − j − 1 ( S D + 1 , d ). Here j is a KR-cycle index, as well as an index counting off the Altland-Zirnbauer classification of Time Reversal Symmetry (TRS) and Particle Hole Symmetry (PHS)—as we show. In this setting, the computation of the invariants can be seen as the evaluation of the natural pairing between KR-cycles and KR-classes. This fits with topological and analytical index computations as well as with Poincaré Duality and the Baum–Connes isomorphism for free Abelian groups. We provide an introduction starting from the basic objects of real, complex and quaternionic structures which are the mathematical objects corresponding to TRS and PHS. We furthermore detail the relevant bundles and K-theories (Real and Quaternionic) that lead to the classification as well as the topological setting for the base spaces. [ABSTRACT FROM AUTHOR]

This is the first of two papers dedicated to the detailed determination of the reduced C*-algebra of a connected, linear, real reductive group up to Morita equivalence, and a new and very explicit proof of the Connes–Kasparov conjecture for these groups using representation theory. In this part we shall give details of the C*-algebraic Morita equivalence and then explain how the Connes–Kasparov morphism in operator K-theory may be computed using what we call the Matching Theorem, which is a purely representation-theoretic result. We shall prove our Matching Theorem in the sequel, and indeed go further by giving a simple, direct construction of the components of the tempered dual that have non-trivial K-theory using David Vogan's approach to the classification of the tempered dual. [ABSTRACT FROM AUTHOR]

This is the second of two papers dedicated to the computation of the reduced C*-algebra of a connected, linear, real reductive group up to C*-algebraic Morita equivalence, and the verification of the Connes–Kasparov conjecture in operator K-theory for these groups. In Part I we presented the Morita equivalence and the Connes–Kasparov morphism. In this part we shall compute the morphism using David Vogan's description of the tempered dual. In fact we shall go further by giving a complete representation-theoretic description and parametrization, in Vogan's terms, of the essential components of the tempered dual, which carry the K-theory of the tempered dual. [ABSTRACT FROM AUTHOR]

We consider the semi-direct products |$G={\mathbb{Z}}^{2}\rtimes GL_{2}({\mathbb{Z}}), {\mathbb{Z}}^{2}\rtimes SL_{2}({\mathbb{Z}})$|⁠ , and |${\mathbb{Z}}^{2}\rtimes \Gamma (2)$| (where |$\Gamma (2)$| is the congruence subgroup of level 2). For each of them, we compute both sides of the Baum–Connes conjecture, namely the equivariant |$K$| -homology of the classifying space |$\underline{E}G$| for proper actions on the left-hand side, and the analytical K-theory of the reduced group |$C^{*}$| -algebra on the right-hand side. The computation of the LHS is made possible by the existence of a 3-dimensional model for |$\underline{E}G$|⁠ , which allows to replace equivariant K-homology by Bredon homology. We pay due attention to the presence of torsion in |$G$|⁠ , leading to an extensive study of the wallpaper groups associated with finite subgroups. For the first and third groups, the computations in |$K_{0}$| provide explicit generators that are matched by the Baum–Connes assembly map. [ABSTRACT FROM AUTHOR]

In this paper, we exhibit two unital, separable, nuclear C∗${\rm C}^*$‐algebras of stable rank one and real rank zero with the same ordered scaled total K‐theory, but they are not isomorphic with each other, which forms a counterexample to the Elliott Classification Conjecture for real rank zero setting. Thus, we introduce an additional normal condition and give a classification result in terms of the total K‐theory. For the general setting, with a new invariant, the total Cuntz semigroup [2], we classify a large class of C∗${\rm C}^*$‐algebras obtained from extensions. The total Cuntz semigroup, which distinguishes the algebras of our counterexample, could possibly classify all the C∗${\rm C}^*$‐algebras of stable rank one and real rank zero. [ABSTRACT FROM AUTHOR]

Persistence modules stratify their underlying parameter space, a quality that makes persistence modules amenable to study via invariants of stratified spaces. In this article, we extend a result previously known only for one-parameter persistence modules to grid multiparameter persistence modules. Namely, we show the K-theory of grid multiparameter persistence modules is additive over strata. This is true for both standard monotone multi-parameter persistence as well as multiparameter notions of zig-zag persistence. We compare our calculations for the specific group K_0 with the recent work of Botnan, Oppermann, and Oudot, highlighting and explaining the differences between our results through an explicit projection map between computed groups. [ABSTRACT FROM AUTHOR]

We initiate the study of K$K$‐theory Soergel bimodules, a global and K$K$‐theoretic version of Soergel bimodules. We show that morphisms of K$K$‐theory Soergel bimodules can be described geometrically in terms of equivariant K$K$‐theoretic correspondences between Bott–Samelson varieties. We thereby obtain a natural categorification of K$K$‐theory Soergel bimodules in terms of equivariant coherent sheaves. We introduce a formalism of stratified equivariant K$K$‐motives on varieties with an affine stratification, which is a K$K$‐theoretic analog of the equivariant derived category of Bernstein–Lunts. We show that Bruhat‐stratified torus‐equivariant K$K$‐motives on flag varieties can be described in terms of chain complexes of K$K$‐theory Soergel bimodules. Moreover, we propose conjectures regarding an equivariant/monodromic Koszul duality for flag varieties and the quantum K$K$‐theoretic Satake. [ABSTRACT FROM AUTHOR]

In this paper, for 1 < p < ∞, the authors show that the coarse ℓp-Novikov conjecture holds for metric spaces with bounded geometry which are coarsely embeddable into a Banach space with Kasparov-Yu's Property (H). [ABSTRACT FROM AUTHOR]

Recently, Ludewig and Thiang introduced a notion of a uniformly localized Wannier basis with localization centers in an arbitrary uniformly discrete subset D in a complete Riemannian manifold X. They show that, under certain geometric conditions on X, the class of the orthogonal projection onto the span of such a Wannier basis in the K-theory of the Roe algebra C*(X) is trivial. In this paper, we clarify the geometric conditions on X, which guarantee triviality of the K-theory class of any Wannier projection. We show that this property is equivalent to triviality of the unit of the uniform Roe algebra of D in the K-theory of its Roe algebra, and provide a geometric criterion for that. As a consequence, we prove triviality of the K-theory class of any Wannier projection on a connected proper measure space X of bounded geometry with a uniformly discrete set of localization centers. [ABSTRACT FROM AUTHOR]

We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds Ug,1n:=#g(Sn×Sn+1)∖int(D2n+1)$U_{g,1}^n:= \#^g(S^n \times S^{n+1})\setminus \mathrm{int}(D^{2n+1})$, for large g$g$ and n$n$, up to degree n−3$n-3$. The answer is that it is a free graded commutative algebra on an appropriate set of Miller–Morita–Mumford classes. Our proof goes through the classical three‐step procedure: (a) compute the cohomology of the homotopy automorphisms, (b) use surgery to compare this to block diffeomorphisms, and (c) use pseudoisotopy theory and algebraic K$K$‐theory to get at actual diffeomorphism groups. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a strongly quasi-local version of the coarse Novikov conjecture, which states that a certain assembly map from the coarse Khomology of a metric space to the K-theory of its strongly quasi-local algebra is injective. We prove that the conjecture holds for metric spaces with bounded geometry which can be coarsely embedded into Banach spaces with Property (H), as introduced by Kasparov and Yu. We also generalize the notion of strong quasi-locality to proper metric spaces and provide a (strongly) quasi-local picture for K-homology. [ABSTRACT FROM AUTHOR]

In this work we will classify physically admissible manifold structures by the use of Waldhausen categories. These categories give rise to algebraic K-Theory. Moreover, we will show that a universal K-spectrum is necessary for a physical manifold being admissible. Application to the generalized structure of D-branes are also provided. This might give novel insights in how the manifold structure in String and M-Theory looks like. [ABSTRACT FROM AUTHOR]

In the area of Early Childhood Education and Care (ECEC), intersubjectivity between the child and the nursery teacher is seen as a core element of professional work. The notion of affect attunement, proposed by Daniel Stern, is central in this regard. Based on ethnographic fieldwork, I explore the relationship between the toddler and the nursery teacher within this frame. However, engaging with perspectives from Actor-Network-Theory, I argue that the interplay is more than mere reciprocal attunement between humans. Through empirical examples, I show how elements such as bibs, sandboxes, wardrobes, rules and routines, all part of the institutional arrangement, are vibrantly at play in the attunement. Thus, I propose the blurry concept of multi-sensitive attunement to point to the heterogeneous connections that make up the relationship. My ambition in exploring and proposing such a blurry concept is to expand our understanding of what goes on in ECEC and what professional work is. It is an ambition to theoretically move the relationship between the toddler and the professional out of an implicit mother-child ideal and into the formalised setting in which it takes place. [ABSTRACT FROM AUTHOR]

For a connected reductive group |$G$| and an affine smooth |$G$| -variety |$X$| over the complex numbers, the localization functor takes |$\mathfrak{g}$| -modules to |$D_{X}$| -modules. We extend this construction to an equivariant and derived setting using the formalism of h-complexes due to Beilinson–Ginzburg, and show that the localizations of Harish-Chandra |$(\mathfrak{g}, K)$| -modules onto |$X = H \backslash G$| have regular holonomic cohomologies when |$H, K \subset G$| are both spherical reductive subgroups. The relative Lie algebra homologies and |$\operatorname{Ext}$| -branching spaces for |$(\mathfrak{g}, K)$| -modules are interpreted geometrically in terms of equivariant derived localizations. As direct consequences, we show that they are finite-dimensional under the same assumptions, and relate Euler–Poincaré characteristics to local index theorem; this recovers parts of the recent results of M. Kitagawa. Examples and discussions on the relation to Schwartz homologies are also included. [ABSTRACT FROM AUTHOR]

We construct uncountably many mutually nonisomorphic simple separable stably finite unital exact C*-algebras that are not isomorphic to their opposite algebras. In particular, we prove that there are uncountably many possibilities for the |$K_0$| -group, the |$K_1$| -group, and the tracial state space of such an algebra. We show that these C*-algebras satisfy the Universal Coefficient Theorem, which is new even for the already known example of an exact C*-algebra nonisomorphic to its opposite algebra produced in an earlier work. [ABSTRACT FROM AUTHOR]

We give a brief review of the cohomological Hall algebra CoHA H and the K-theoretical Hall algebra KHA R associated to quivers. In the case of symmetric quivers, we show that there exists a homomorphism of algebras (obtained from a Chern character map) R → H ˆ σ ˜ where H ˆ σ ˜ is a Zhang twist of the completion of H. Moreover, we establish the equivalence of categories of "locally finite" graded modules H - Mod l f ≃ R Q - Mod l f. Examples of locally finite H ˆ -, resp. R Q -modules appear naturally as the cohomology, resp. K-theory, of framed moduli spaces of quivers. [ABSTRACT FROM AUTHOR]

We define higher semiadditive algebraic K-theory, a variant of algebraic K-theory that takes into account higher semiadditive structure, as enjoyed for example by the $\mathrm {K}(n)$ - and $\mathrm {T}(n)$ -local categories. We prove that it satisfies a form of the redshift conjecture. Namely, that if $R$ is a ring spectrum of height $\leq n$ , then its semiadditive K-theory is of height $\leq n+1$. Under further hypothesis on $R$ , which are satisfied for example by the Lubin–Tate spectrum $\mathrm {E}_n$ , we show that its semiadditive algebraic K-theory is of height exactly $n+1$. Finally, we connect semiadditive K-theory to $\mathrm {T}(n+1)$ -localized K-theory, showing that they coincide for any $p$ -invertible ring spectrum and for the completed Johnson–Wilson spectrum $\widehat {\mathrm {E}(n)}$. [ABSTRACT FROM AUTHOR]

Let A be an associative ring and M a finitely generated projective A-module. We introduce a category RBS (M) and prove several theorems which show that its geometric realisation functions as a well-behaved unstable algebraic K-theory space. These categories RBS (M) naturally arise as generalisations of the exit path ∞ -category of the reductive Borel–Serre compactification of a locally symmetric space, and one of our main techniques is to find purely categorical analogues of some familiar structures in these compactifications. [ABSTRACT FROM AUTHOR]

K-theoretic Hall algebras (KHAs) of quivers with potential (Q, W) are a generalization of preprojective KHAs of quivers, which are conjecturally positive parts of the Okounkov–Smironov quantum affine algebras. In particular, preprojective KHAs are expected to satisfy a Poincaré–Birkhoff–Witt theorem. We construct semi-orthogonal decompositions of categorical Hall algebras using techniques developed by Halpern-Leistner, Ballard–Favero–Katzarkov, and Špenko–Van den Bergh. For a quotient of KHA (Q , W) Q , we refine these decompositions and prove a PBW-type theorem for it. The spaces of generators of KHA (Q , 0) Q are given by (a version of) intersection K-theory of coarse moduli spaces of representations of Q. [ABSTRACT FROM AUTHOR]

Let k be an algebraically closed field of characteristic zero. We prove that the Brauer group of the moduli stack of stable parabolic PGL (r , k) -bundles on a smooth projective curve, with full flag quasi-parabolic structures at an arbitrary parabolic divisor, coincides with the Brauer group of the smooth locus of the corresponding coarse moduli space of parabolic PGL (r , k) -bundles. We also compute the Brauer group of the smooth locus of this coarse moduli for more general quasi-parabolic types and weights satisfying certain conditions. [ABSTRACT FROM AUTHOR]

A recent theorem by T. Barthel, M. Hausmann, N. Naumann, T. Nikolaus, J. Noel, and N. Stapleton says that if A is a finite abelian p-group of rank r, then any finite A-space X which is acyclic in the nth Morava K-theory with n ⩾ r will have its subspace XA of fixed points acyclic in the (n - r)th Morava Ktheory. This is a chromatic homotopy version of P. A. Smith's classical theorem that if X is acyclic in mod p homology, then so is XA. The main purpose of this paper is to give an elementary proof of this new theorem that uses minimal background, and follows, as much as possible, the reasoning in standard proofs of the classical theorem. We also give a new fixed point theorem for finite dimensional, but possibly infinite, A-CW complexes, which suggests some open problems. [ABSTRACT FROM AUTHOR]

Gromov proved a quadratic decay inequality of scalar curvature for a class of complete manifolds. In this paper, we prove that for any uniformly contractible manifold with finite asymptotic dimension, its scalar curvature decays to zero at a rate depending only on the contractibility radius of the manifold and the diameter control of the asymptotic dimension. We construct examples of uniformly contractible manifolds with finite asymptotic dimension whose scalar curvature functions decay arbitrarily slowly. This shows that our result is the best possible. We prove our result by studying the index pairing between Dirac operators and compactly supported vector bundles with Lipschitz control. A key technical ingredient for the proof of our main result is a Lipschitz control for the topological K‐theory of finite dimensional simplicial complexes. [ABSTRACT FROM AUTHOR]

Working in a polynomial ring S=k[x1,...,xn]$S={\mathbf {k}}[x_1,\ldots ,x_n]$, where k${\mathbf {k}}$ is an arbitrary commutative ring with 1, we consider the d$d$th Veronese subalgebras R=S(d)$R={S^{(d)}}$, as well as natural R$R$‐submodules M=S(⩾r,d)$M={S^{({\geqslant r},{d})}}$ inside S$S$. We develop and use characteristic‐free theory of Schur functors associated to ribbon skew diagrams as a tool to construct simple GLn(k)$GL_n({\mathbf {k}})$‐equivariant minimal free R$R$‐resolutions for the quotient ring k=R/R+${\mathbf {k}}=R/R_+$ and for these modules M$M$. These also lead to elegant descriptions of ToriR(M,M′)$\operatorname{Tor}^R_i(M,M^{\prime})$ for all i$i$ and HomR(M,M′)$\operatorname{Hom}_R(M,M^{\prime})$ for any pair of these modules M,M′$M,M^{\prime}$. [ABSTRACT FROM AUTHOR]

We revisit the 3d GLSM computation of the equivariant quantum K-theory ring of the complex Grassmannian from the perspective of line defects. The 3d GLSM onto X = Gr(Nc, nf) is a circle compactification of the 3d N = 2 supersymmetric gauge theory with gauge group U N c k , k + l N c and nf fundamental chiral multiplets, for any choice of the Chern-Simons levels (k, l) in the 'geometric window'. For k = N c − n f 2 and l = −1, the twisted chiral ring generated by the half-BPS lines wrapping the circle has been previously identified with the quantum K-theory ring QKT(X). We identify new half-BPS line defects in the UV gauge theory, dubbed Grothendieck lines, which flow to the structure sheaves of the (equivariant) Schubert varieties of X. They are defined by coupling N = 2 supersymmetric gauged quantum mechanics of quiver type to the 3d GLSM. We explicitly show that the 1d Witten index of the defect worldline reproduces the Chern characters for the Schubert classes, which are written in terms of double Grothendieck polynomials. This gives us a physical realisation of the Schubert-class basis for QKT(X). We then use 3d A-model techniques to explicitly compute QKT(X) as well as other K-theoretic enumerative invariants such as the topological metric. We also consider the 2d/0d limit of our 3d/1d construction, which gives us local defects in the 2d GLSM, the Schubert defects, that realise equivariant quantum cohomology classes. [ABSTRACT FROM AUTHOR]

We establish connections between the concepts of Noetherian, regular coherent, and regular n-coherent categories for Z -linear categories with finitely many objects and the corresponding notions for unital rings. These connections enable us to obtain a negative K-theory vanishing result, a fundamental theorem, and a homotopy invariance result for the K-theory of Z -linear categories. [ABSTRACT FROM AUTHOR]

Let F be a non-archimedean local field with residue field \mathbb {F}_q and let \mathbf {G}=GL_{2/F}. Let \mathbf {q} be an indeterminate and let \mathcal {H}^{(1)}(\mathbf {q}) be the generic pro-p Iwahori-Hecke algebra of the p-adic group \mathbf {G}(F). Let V_{\mathbf {\widehat {G}}} be the Vinberg monoid of the dual group \mathbf {\widehat {G}}. We establish a generic version for \mathcal {H}^{(1)}(\mathbf {q}) of the Kazhdan-Lusztig-Ginzburg spherical representation, the Bernstein map and the Satake isomorphism. We define the flag variety for the monoid V_{\mathbf {\widehat {G}}} and establish the characteristic map in its equivariant K-theory. These generic constructions recover the classical ones after the specialization \mathbf {q}=q\in \mathbb {C}. At \mathbf {q}=q=0\in \overline {\mathbb {F}}_q, the spherical map provides a dual parametrization of all the irreducible \mathcal {H}^{(1)}_{\overline {\mathbb {F}}_q}(0)-modules. [ABSTRACT FROM AUTHOR]

Structures where we have both a contravariant (pullback) and a covariant (pushforward) functoriality that satisfy base change can be encoded by functors out of ($\infty$ -)categories of spans (or correspondences). In this paper, we study the more complicated setup where we have two pushforwards (an 'additive' and a 'multiplicative' one), satisfying a distributivity relation. Such structures can be described in terms of bispans (or polynomial diagrams). We show that there exist $(\infty,2)$ -categories of bispans, characterized by a universal property: they corepresent functors out of $\infty$ -categories of spans where the pullbacks have left adjoints and certain canonical 2-morphisms (encoding base change and distributivity) are invertible. This gives a universal way to obtain functors from bispans, which amounts to upgrading 'monoid-like' structures to 'ring-like' ones. For example, symmetric monoidal $\infty$ -categories can be described as product-preserving functors from spans of finite sets, and if the tensor product is compatible with finite coproducts our universal property gives the canonical semiring structure using the coproduct and tensor product. More interestingly, we encode the additive and multiplicative transfers on equivariant spectra as a functor from bispans in finite $G$ -sets, extend the norms for finite étale maps in motivic spectra to a functor from certain bispans in schemes, and make $\mathrm {Perf}(X)$ for $X$ a spectral Deligne–Mumford stack a functor of bispans using a multiplicative pushforward for finite étale maps in addition to the usual pullback and pushforward maps. Combining this with the polynomial functoriality of $K$ -theory constructed by Barwick, Glasman, Mathew, and Nikolaus, we obtain norms on algebraic $K$ -theory spectra. [ABSTRACT FROM AUTHOR]

This paper describes a relation between the elliptic stable envelopes of a hypertoric variety X and a distinguished K-theory class on the product of the loop hypertoric space L ~ X and its symplectic dual P X ! . This class intertwines the K-theoretic stable envelopes in a certain limit. Our results are suggestive of a possible categorification of elliptic stable envelopes. [ABSTRACT FROM AUTHOR]

In the quest for mathematical foundations of M-theory, the Hypothesis H that fluxes are quantized in Cohomotopy theory, implies, on flat but possibly singular spacetimes, that M-brane charges locally organize into equivariant homotopy groups of spheres. Here, we show how this leads to a correspondence between phenomena conjectured in M-theory and fundamental mathematical concepts/results in stable homotopy, generalized cohomology and Cobordism theory M f : — stems of homotopy groups correspond to charges of probe p -branes near black b -branes; — stabilization within a stem is the boundary-bulk transition; — the Adams d-invariant measures G 4 -flux; — trivialization of the d-invariant corresponds to H 3 -flux; — refined Toda brackets measure H 3 -flux; — the refined Adams e-invariant sees the H 3 -charge lattice; — vanishing Adams e-invariant implies consistent global C 3 -fields; — Conner–Floyd's e-invariant is the H 3 -flux seen in the Green–Schwarz mechanism; — the Hopf invariant is the M2-brane Page charge ( G ̃ 7 -flux); — the Pontrjagin–Thom theorem associates the polarized brane worldvolumes sourcing all these charges. In particular, spontaneous K3-reductions with 24 branes are singled out from first principles : — Cobordism in the third stable stem witnesses spontaneous KK-compactification on K3-surfaces; — the order of the third stable stem implies the 24 NS5/D7-branes in M/F-theory on K3. Finally, complex-oriented cohomology emerges from Hypothesis H, connecting it to all previous proposals for brane charge quantization in the chromatic tower: K-theory, elliptic cohomology, etc. : — quaternionic orientations correspond to unit H 3 -fluxes near M2-branes; — complex orientations lift these unit H 3 -fluxes to heterotic M-theory with heterotic line bundles. In fact, we find quaternionic/complex Ravenel-orientations bounded in dimension; and we find the bound to be 10, as befits spacetime dimension 1 0 + 1. [ABSTRACT FROM AUTHOR]

We present a decomposition of rational twisted G-equivariant K-theory, G a finite group, into cyclic group equivariant K-theory groups of fixed point spaces. This generalises the untwisted decomposition by Atiyah and Segal [J. Geom. Phys. 6 (1989), pp. 671–677] as well as the decomposition by Adem and Ruan [Comm. Math. Phys. 237 (2003), pp. 533–556] for twists coming from group cocycles. [ABSTRACT FROM AUTHOR]

Borel's rank theorem identifies the ranks of algebraic K-groups of the ring of integers of a number field with the orders of vanishing of the Dedekind zeta function attached to the field. Following the work of Gross, we establish a version of this theorem for Artin L-functions by considering equivariant algebraic K-groups of number fields with coefficients in rational Galois representations. This construction involves twisting algebraic K-theory spectra with rational equivariant Moore spectra. We further discuss integral equivariant Moore spectra attached to Galois representations and their potential applications in L-functions. [ABSTRACT FROM AUTHOR]

We establish a formula for the L‐theory spectrum of real C∗$C^*$‐algebras from which we deduce a presentation of the L‐groups in terms of the topological K‐groups, extending all previously known results of this kind. Along the way, we extend the integral comparison map τ:k→L$\tau \colon \mathrm{k}\rightarrow \mathrm{L}$ obtained in previous work by the first two authors to real C∗$C^*$‐algebras and interpret it using topological Grothendieck–Witt theory. Finally, we use our results to give an integral comparison between the Baum–Connes conjecture and the L‐theoretic Farrell–Jones conjecture, and discuss our comparison map τ$\tau$ in terms of the signature operator on oriented manifolds. [ABSTRACT FROM AUTHOR]

Some multiplication is constructed for algebraic K-functors of the crossed products of a commutative algebra and a Hopf cocommutative algebra; the question on these functors to be Frobenius functors with respect to the constructed multiplication is studied. [ABSTRACT FROM AUTHOR]

We prove that the Hilbert scheme of k points on C 2 ( Hilb k [ C 2 ] ) is self-dual under three-dimensional mirror symmetry using methods of geometry and integrability. Namely, we demonstrate that the corresponding quantum equivariant K-theory is invariant upon interchanging its Kähler and equivariant parameters as well as inverting the weight of the C ħ × -action. First, we find a two-parameter family X k , l of self-mirror quiver varieties of type A and study their quantum K-theory algebras. The desired quantum K-theory of Hilb k [ C 2 ] is obtained via direct limit l ⟶ ∞ and by imposing certain periodic boundary conditions on the quiver data. Throughout the proof, we employ the quantum/classical (q-Langlands) correspondence between XXZ Bethe Ansatz equations and spaces of twisted ħ -opers. In the end, we propose the 3d mirror dual for the moduli spaces of torsion-free rank-N sheaves on P 2 with the help of a different (three-parametric) family of type A quiver varieties with known mirror dual. [ABSTRACT FROM AUTHOR]

We study groupoids and semigroup |$C^{\ast }$| -algebras arising from graphs of monoids, in the setting of right LCM monoids. First, we establish a general criterion when a graph of monoids gives rise to a submonoid of the fundamental group that is right LCM. Moreover, we carry out a detailed analysis of structural properties of semigroup |$C^{\ast }$| -algebras arising from graphs of monoids, including closed invariant subspaces and topological freeness of the groupoids, as well as ideal structure, nuclearity, and K-theory of the semigroup |$C^{\ast }$| -algebras. As an application, we construct families of pairwise nonconjugate Cartan subalgebras in every UCT Kirchberg algebra. [ABSTRACT FROM AUTHOR]