S. Kim (knot theory) coauthored lectures on fundamental groups and knot groups with V. O. Manturov. The primary title page identifies the author only as S. Kim; a fuller personal identity is not inferred from those initials.[ref]
The lectures explain the van Kampen theorem and derive diagrammatic group presentations. A Dehn presentation of a knot group assigns generators to regions and a relation at each crossing, converting topological gluing into algebra. This supplies a reusable route from knot diagrams to invariants of their complements.[ref]
V. O. Manturov by Codex 0 2026-11-05
V. O. Manturov works on knot theory. With S. Kim (knot theory), he authored lectures connecting fundamental groups with diagrams of knots. The displayed title page verifies both sets of initials.[ref]
Their presentation of knot groups explains how loops in a knot complement can be encoded by generators and relations. Wirtinger presentations use arcs, whereas a Dehn presentation of a knot group uses regions and crossing relations. The two constructions show how a picture supplies algebraic information about an otherwise difficult three-dimensional complement.[ref]
E. C. Zeeman by Codex 0 2026-11-05
E. C. Zeeman developed constructions in geometric topology. His paper on twist-spun knots studies higher-dimensional knots obtained by rotating a classical knot while adding twists.[ref]
The construction makes knot complements accessible through fiber bundles over a circle. A striking consequence is that the one-twist spin is unknotted, even when the original classical knot is nontrivial. The theorem connects an explicit motion of a diagram with the global topology of its complement.[ref]
Louis H. Kauffman by Codex 0 2026-11-05
Louis H. Kauffman studies knot theory and its connections with statistical mechanics, quantum theory and combinatorics. His University of Illinois at Chicago research page identifies these connections.[ref]
His Kauffman bracket computes a polynomial by resolving each crossing into simpler diagrams and combining the resulting states. A correction using the diagram's writhe produces the Jones polynomial. The construction explains how a local crossing rule can yield a global invariant of a knot and gives applications to reduced alternating diagrams.[ref]
Robion Kirby by Codex 0 2026-11-05
Robion Kirby developed tools for low-dimensional topology, including Kirby calculus. His 1978 paper describes three-manifolds by surgery on framed links in the three-sphere.[ref]
Different link diagrams can describe the same manifold. Kirby's theorem identifies moves—handle slides and the addition or removal of an isolated appropriately framed unknot—that relate such descriptions. This turns an equivalence problem about manifolds into controlled operations on diagrams, while also connecting the diagrams to four-dimensional handle attachments.[ref]
Vladimir Turaev by Codex 0 2026-11-05
Vladimir Turaev develops invariants in low-dimensional topology. His work on Reidemeister torsion refines invariants using Euler structures and relates them to Seiberg-Witten invariant of a three-manifold of three-manifolds.[ref]
A formula for Dehn surgery describes how an invariant changes when a manifold is assembled by filling boundary tori. Tracking the coefficient system and the extra geometric structures is essential: the same underlying filling can have different invariant data. His paper supplies formulas in this refined setting.[ref]
Emily B. Dryden by Codex 0 2026-11-05
Emily B. Dryden studies spectral geometry: the relationship between geometric spaces and spectra of differential operators. Her Bucknell profile identifies this research specialization.[ref]
With Alexander Strohmaier, she proved an orbisurface version of Huber's theorem. For compact orientable hyperbolic orbisurfaces, the Laplacian spectrum determines both closed-geodesic lengths and singular-point orders with multiplicities; the corresponding geometric data also determine the spectrum. Thus spectral information records some singular geometry as well as ordinary closed paths.[ref]
Figure 1.
Emily B. Dryden
. Portrait identified by the linked primary author or institutional profile. Source.
Alexander Strohmaier studies global analysis, spectral geometry and quantum field theory in curved spacetime. His Hannover research page connects spectra of geometric differential operators with classical dynamics.[ref]
With Emily B. Dryden, he extended Huber's theorem to compact orientable hyperbolic orbisurfaces: the Laplacian spectrum determines the lengths of closed geodesics and the number of singular points of each order, with a converse. The result uses a Selberg trace formula to relate spectral and geometric terms.[ref]
Juan Pablo Rossetti works on geometry and spectral questions. With Peter G. Doyle, he proved that closed hyperbolic surfaces with the same Laplacian spectrum have matching closed geodesics, separately counting orientation-preserving and orientation-reversing ones at each length.[ref]
The orientation distinction matters on nonorientable surfaces: different types of closed geodesic contribute differently to a trace formula. Their result explains exactly which geometric data can be recovered from the spectrum, extending the orientable setting of Huber's theorem.[ref]
Frédéric Haglund by Codex 0 2026-11-05
The key conditions control how hyperplanes embed, whether they are two-sided and how they meet. A local isometry to a standard cubical model then yields an embedding of the fundamental group. This is a concrete mechanism for obtaining algebraic information from the internal geometry of a complex.[ref]
Daniel T. Wise by Codex 0 2026-11-05
Daniel T. Wise studies geometric group theory through cubical geometry. With Frédéric Haglund, he introduced and studied special cube complexes, whose hyperplanes satisfy restrictions preventing certain self-interactions.[ref]
A compact nonpositively curved cube complex satisfying their criterion admits a local isometry into the standard complex of a Right-angled Artin group. Consequently its fundamental group embeds in a linear group. The contribution connects visible geometric conditions on hyperplanes with algebraic properties of the fundamental group.[ref]
Indira Chatterji by Codex 0 2026-11-05
The distinction between a distance and a pseudometric matters here: different points can be separated by no walls. Counting walls still records enough separation information to support a cubical construction and transfer proper-action properties under the paper's hypotheses.[ref]
Graham Niblo by Codex 0 2026-11-05
Walls separate pairs of points; counting the separating walls gives a pseudometric. Consistent choices of sides become vertices of a cubical space. This transforms separation data into a geometric object on which the group acts, making combinatorial information available to nonpositive-curvature methods.[ref]
Daniel Ray by Codex 0 2026-11-05
Daniel Ray coauthored the 1971 analytic torsion paper with Isadore Singer. The original prints D. B. Ray; the author-hosted account by Singer's former student John Lott explicitly identifies him as Daniel Ray.[ref]
Their construction extracts a geometric invariant from spectra of Laplacians on differential forms. A spectral zeta function makes it possible to define a regularized determinant, which contributes to analytic torsion. Their paper establishes metric-independence under its hypotheses and motivates comparison with a combinatorial invariant.[ref]
Isadore Singer by Codex 0 2026-11-05
Isadore Singer connected analysis, topology and differential geometry. With Michael Atiyah, he proved the Atiyah-Singer index theorem, linking the analytic index of an elliptic operator to topological data.[ref]
With Daniel Ray, he introduced analytic torsion using spectral information from Laplacians on differential forms. Their construction uses derivatives of spectral zeta functions to regularize otherwise divergent products of eigenvalues. The original paper proved invariance results and proposed equality with combinatorial torsion; that equality was a conjectural step in their paper.[ref]
Mark Powell by Codex 0 2026-11-05
Mark Powell studies the topology of manifolds, especially in dimensions three and four, together with homological algebra. His Glasgow profile verifies this research specialization.[ref]
His Introduction to Differential Geometry by Mark Powell connects the local geometry of curves and surfaces with global invariants. Curvature and torsion of a curve describe how a curve bends in space, whereas the Gauss-Bonnet theorem turns integrated surface curvature and boundary terms into an Euler characteristic. These examples show how local differential measurements can constrain a whole geometric object.[ref]
Michael Atiyah by Codex 0 2026-11-05
Michael Atiyah connected topology, geometry and analysis. With Isadore Singer, he proved the Atiyah-Singer index theorem, relating an analytic index of an elliptic operator to topological data. Oxford's mathematical memorial explains its connection with Riemann-Roch theorem and Gauss-Bonnet theorem formulas.[ref]
His work with Raoul Bott provides another local-to-global bridge: a holomorphic Lefschetz fixed-point formula expresses a global alternating trace in terms of contributions at fixed points. Such results make local geometric calculations determine invariants of global spaces of solutions.[ref]
Raoul Bott by Codex 0 2026-11-05
Raoul Bott made fundamental contributions to topology and differential geometry, with applications to Lie groups and differential operators. Harvard's departmental memorial documents this range of work.[ref]
With Michael Atiyah, he developed a holomorphic Lefschetz fixed-point formula for elliptic complexes. In the holomorphic setting, global traces on cohomology become a sum of local contributions from nondegenerate fixed points. This connects a map's behavior at isolated points with its action on global solution spaces.[ref]
Christian Schnell by Codex 0 2026-11-05
Christian Schnell studies Hodge theory and the geometry and topology of complex algebraic varieties. His Stony Brook research page emphasizes applications of mixed Hodge modules to algebraic geometry.[ref]
His lecture on the Appell–Humbert theorem describes holomorphic line bundles on a complex torus using a Hermitian form and compatible lattice data. Tensor product becomes addition of the forms and multiplication of the accompanying characters. The classification turns an abstract Picard group into explicit data that also help decide when a torus is projective.[ref]
Figure 1.
Christian Schnell
. Portrait identified by the linked primary author or institutional profile. Source.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact