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From the Obsidian Second Brain

Follow the connections.

146 public records, 14 topic maps, and six reading routes. Select an area, find a paper, or follow a documented reference. The topic hubs follow the layout of the vault’s Research Map.

PaperLarge circles: topics · lines: topic membership146 records shown
6Algebra and algebraicgeometry22Banach spaces andBanach lattices9Combinatorics and Ramseytheory9Geometric group theory7Groupoids and Cartanpairs46Homological algebra andderived limits1Ideals and convergence7Lattices and orderedalgebra10Measure and ergodictheory8Model theory anddefinability32Operator algebras16Ordered groups40Polish groups anddescriptive complexity33Topological dynamics andamenabilityOrder extension in Chehata's groupGroups with prescribed finite numbers of lattice ordersFinite configurations and nuclear quotients of Thompson's group FCharmenability of Thompson's group FNormal-semigroup generators for the bi-order cones of Thompson's group F′Failure of rational injectivity for minimal principal étale groupoidsOrder-universal free subgroups and bi-order extensionFinite incidence models for elliptic resonance varietiesA finitely presented nonindicable subgroup of a free profinite groupNonmeagre ideals from traces on corona algebrasLocal units and multiplier algebras of AF corona idealsJordan spectra of nilpotent derivations from scalar geometryThe noncommutative weak extension principle under OCAPositive normal identities and bi-order extensionSimple left-orderable groups with prescribed finiteness lengthSemiprojectivity and norm-controlled lifting in Banach latticesAscending chains of sublattices in free latticesOrder, norming faces, and symmetries of Tursi's Banach latticeForests as Heyting spectra: representation criteria, constructions, and obstructionsEndomorphism counts from primitive orbits and synchronized block actionsA countable scattered poset without a strongly maximal chainThe small index property for the random posetSimultaneous avoidance of power families of null sequencesA countable norm construction for free Banach lattices under arbitrary convexity implicationsGeometric criteria for the sequential Dini propertyPeripheral eigenspace dimensions for positive operators and semigroupsLipschitz positive decompositions of von Neumann predualsIsometric canonical maps into free convex Banach latticesCommon null complements for polynomial images of finite sums of perfect setsCritical ideals and covering widths of ideal Schauder basesUniversal minimal flows from pointwise completions and atomic decompositionSpectral criteria for extending partial left ordersCompletely positive coordinates for KK-theory and relative uniform stabilityPairwise mixing layouts and self-joinings of weakly mixing transformationsRobust fixed points and finite classifying spaces: CAT(0) actions, Banach targets and group fillingsIsomorphism is strictly Borel reducible to quasi-isometry for finitely generated groupsBi-orderable soluble groups with only Conradian left ordersThompson's group F′ is an O*-group: Positive conjugacy semigroups in Thompson's group F′Saturation and equational hulls of ordered semigroup varietiesAmalgamation in an infinite chain of commutative idempotent residuated-lattice varietiesThe variety of integral residuated lattices fails the amalgamation propertyIsomorphism and bi-embeddability of countable Archimedean ordered groupsPolarities, voltages, and capacitors: a categorical approach to hulls, envelopes, and completionsLipschitz embeddings of symmetric operator-ideal balls into Hilbert spaceBounded coordinate lengths and normal closures in Polish productsA universal Banach–Mazur stability radius for von Neumann algebrasPolynomial estimates for K-convexity from Walsh decay and cotypeRecursive classification and admissible descent for preliminary C*-algebras with prescribed weighted spectrumSpectral ranks and dynamical lengths of preliminary C*-algebrasSupport rings, Polishability, and the SIN propertyProximally irreducible affine extensions: composition and maximal coversA counterexample to the Global Glimm ProblemFinite sums and idempotency for dynamically central piecewise syndetic setsPointwise convergence of bilinear averages for two commuting transformationsExactness and amenability at infinity for locally compact groupoidsDynamical spectra of unital C*-algebras: AF realizations and Cartan pairsInjective and projective objects in categories of topological torsion Polish abelian groupsDynamical length of Cartan pairs: comparison, rigidity, and invarianceEfficient contractions of the Urysohn isometry groupBounded geometry in Polish groups: locally compact models, amenability, and simple examplesPointwise bounded cocycles and coarse decompositions of topological groupsBoundedness exponents of unitary function groups and measured full groupsExact boundedness exponents for permutation and automorphism groupsQuantitative boundedness in homeomorphism groupsFixed words, function groups, and exact odd boundedness exponentsFixed-exponent boundedness and cocompact permanence in Polish groupsSolution to Dixmier's Problem about spectra of C*-algebrasAutomatic equivariant Jiang–Su stability in the nonunital tracial settingSharp Borel representation dimensions for compact arithmetic actionsArithmetic denominators and ordinary compact orbit comparisonsMeasurable signatures and algebraic structure of L¹ full groupsLocal swaps, Polish group topologies, and automorphisms of L¹ full groupsPolish topologies and coset obstructions for measurable transformation groupsA three-generated abelian lattice-ordered group without an existentially closed prime extensionDistributivity of lattice-ordered pregroupsLocal fields and ordinary affine Borel comparisonsConvex normal subgroups of ℓ-simple lattice-ordered groupsTame functions and Asplund representations of additive Banach groupsPolishability from orbit reducibility of coset equivalence relationsThe linear isometry group of the Holmes spaceUniversal minimal flows of automorphism groups of locally finite treesThe Artin group of type $E_8$ and the left-orderability of spherical Artin groupsInjective objects in the category of Polish abelian groupsConstructive normal identities in metabelian groupsAn eight-element parachute lattice and its dual: finite representations with two unary operationsA countable lattice-ordered group not latticeisomorphic to any abelian oneProperty (OB) and the Coarse Geometry of Polish Groups --- Fixed Exponents, Permanence, and ApplicationsLattice-Ordered Groups as Full Automorphism Groups of PosetsA subdirect product of Ohkuma groups with nonunique additionContinuous Lipschitz spaces on topometric spaces and free-space dynamicsThe countable cube with the supremum metric is not Lipschitz universalNorm formulas, independence, and spaces of typesRosenthal representations of homogeneous spaces: rank-one classifications and higher-rank criteriaLow-complexity factors of compact affine semigroup actionsConvergence relations of pro-Lie Polish groupsIsomorphism of finitely generated bi-orderable elementary amenable groups is universalRank-two and two-prime rigidity in Borel classification problemsOrdered Compactifications and Circular Ellis SemigroupsUniform cohomological gaps and operator-local repairSkew-amenability in finite-regularity topologies for path, loop, and gauge groupsNonabelian extensions of Solecki's coset dichotomyTwisted Iwahori gluing and central extensions of SL2(Z[1/2])Charmenability of Leavitt unit groups and Clifford-lamp groupsUCT-universal nuclear quotients of a binary wreath productCongruence stability for an Iwahori gluing problemContractibility and Banach-space representations of the Carderi--Thom groupsLoCoLoCo Polish subgroups and the non-Archimedean complexity spectrumJoint Euler-cocycle estimates and simplicial volume of surface bundles$\mathbf{\Sigma^0_2}$ boundaries in $\ell^1$-homology from amenable convergence actionsA matrix convexity characterization of the noncommutative Poulsen simplexMalliavin--Malliavin and whirly amenability: Borel observations, translation displacement, and total variationDistortion of Banach-space unit spheres under their linear isometry groupsGeneric monothetic subgroups of the measure automorphism groupUniversal minimal flows of homeomorphism groups of solenoids and Knaster continuaExactness of strong unitary groups associated with discrete groups with the approximation propertyUniversal minimal flows of automorphism groups\\of stable Kirchberg algebrasUniversal minimal flows for unital Kirchberg and AF algebrasCircular colorings of abelian Cayley graphs below fourBorel invariant means on countable inverse limits of amenable groupsWhirly monothetic groups that are not L\'evyAmenability and skew-amenability of C1 path, loop, and one-dimensional gauge groupsConcentrating measures and whirly amenability of Doucha's universal metric groupL\'evy stabilizers of the Poulsen simplex, the Gurarij space, and their noncommutative analoguesUniversal minimal flows of inductive limits of Lie groupsA counterexample to the (approximate) Universal Coefficient Theorem for \texorpdfstring{$K$}{K}-homology of C*-algebrasExtreme amenability of the automorphism group of the Jiang-Su algebraExtreme amenability of the automorphism group of the Razak-Jacelon algebraUniversal minimal flows of Cuntz automorphism and unitary groupsExtreme amenability of the additive group of $L^p$ for $0<p<1$Borel-definable homological algebra for locally compact Polish modules over rings of integersHomological algebra of pro-Lie Polish modules over rings of integersDescriptive classification of classes of C*-algebras and locally compact groupsHomogeneity of complete M-faces of the noncommutative Poulsen simplexThe franks of Moore groupsDerived limits and the phantom spectrum of Fréchet-Schwartz spacesCorrigendum to "Complexity Classes of Polishable Subgroups"Dynamical spectra of separable unital scattered $C^*$-algebras and Cartan pairsCohomological lengths of groupoidsNormalizer correction and relative derivation and automorphism lengths for Cartan C*-subalgebrasDerivation length and automorphism length of unital C*-algebrasOn the Borel complexity of operator imagesOn Niemiec's Universal Valued GroupsC*-algebras of all successor ordinal derivation and automorphism lengthsDerived limits and phantom filtrations for towers of locally compact Polish abelian groupsThe Descriptive Complexity of Nonabelian $\boldsymbol{\lim^1}$Bratteli graphs

Positions aid navigation; distance does not measure mathematical similarity. References were captured in the vault and are not proof dependencies.

Six routes through the archive

Read across the boundaries.

These are proposed syntheses from the Second Brain, not new results or established proof dependencies. Only papers already present in this public catalog are linked here.

Proposed reading route

Classification beyond fixed invariants

The fixed-invariant manuscript constructs E₀ classification inside families sharing a full Elliott invariant and comparison radius. The trace-dynamics manuscript codes homeomorphism conjugacy into cocycle conjugacy. Both illustrate the role of descriptive complexity after familiar invariants have been fixed.

Keep separate: E₀ bireducibility, universality for Polish group orbit relations, and failure of classification by countable structures are distinct claims. Fixed first-order theory is an additional assertion in the fixed-invariant family, not a consequence of every Borel coding.

2 additional source notes are outside this catalog edition.

Proposed reading route

Dynamical lengths, spectra, and Cartan pairs

The Cartan-pair draft organizes five length coordinates and their invariance properties. The AF-spectrum draft classifies realizable values and explicitly imports an exclusion theorem from a companion. The primitive-ideal and Fell–Pedersen drafts examine how topological and rank data constrain dynamical lengths.

Keep separate: Track absolute algebra invariants, pair invariants, and groupoid invariants separately. The Cartan abstract identifies a low-complexity case in which the twist can affect one coordinate. The earlier Fell/Pedersen rank paper and its dynamical-length companion have separate identities.

2 additional source notes are outside this catalog edition.

Proposed reading route

Ideals, bases, and reconstruction

The critical-ideal manuscript constructs ideals from errors of basis expansions. The convergence manuscript builds Polishable groups from ideals. The reconstruction paper asks what those groups remember about the starting ideal.

Keep separate: Keep equality, isomorphism of ideals, Rudin–Blass comparisons, and Katětov equivalence separate. The critical-ideal result up to isomorphism and the reconstruction result up to Katětov equivalence answer different questions.

2 additional source notes are outside this catalog edition.

Proposed reading route

Positive identities and order extension

These drafts connect positivity constraints with algebraic and algorithmic structure. The positive-normal-identity draft states undecidability in fixed free groups; the universal-subgroup draft transfers bi-order extension problems; the common-multiple draft gives a positive theorem for abelian-by-nilpotent groups.

Keep separate: The common-multiple theorem concerns nilpotent coefficient groups and nonnegative coefficients. It does not supply an algorithm for the free-group problems. Arithmetic interpretation in free lattice-ordered groups is another kind of definability statement.

2 additional source notes are outside this catalog edition.

Proposed reading route

Symmetry, concentration, and boundedness

The library contains concentration and Lévy stabilizer constructions, formulas for universal minimal flows, automatic continuity for a homogeneous poset, and a separate collection on quantitative boundedness of Polish groups. Their shared objects are symmetry groups with additional topological or metric structure.

Keep separate: Distinguish amenability, extreme amenability, whirly amenability, concentration, and Property (OB). Record the topology and whether an assertion concerns arbitrary abstract homomorphisms or only continuous actions.

Proposed reading route

Uniform lifting and perturbation

The completely positive correction draft controls a correction using a uniform defect. The recursive-subhomogeneous stability draft states a control function independent of pullback length and matrix sizes. The Banach-lattice semiprojectivity draft formulates almost contractive lifting through ideal quotients.

Keep separate: These are comparisons of proof organization across different categories. A Banach-lattice homomorphism and a C*-algebra *-homomorphism satisfy different requirements. Separate fixed parameters, uniform constants, and dependencies on domain or target.

1 additional source note is outside this catalog edition.

Source: uploaded Second Brain, checked 5 November 2026. 149 vault notes match the 146 public records; version duplicates are consolidated. Personal notes, local paths, and private manuscript links are not included.