© | Dror Bar-Natan: Academic Pensieve: | Random |
Recent prefixes: Murphy Martchenkov LiuJ Dancso Hogan Dror VanDerVeen Bosch Afeke Fiedler KAL Frohlich Boyle Jiang Munasinghe PoleDancing
All prefixes: 08401 09240 10_327 11_1100 12_240 12_267 14_1100 15-344 15-475 16-1750 16-475 1617-257 17-1750 18-327 18S-AKT 2122-257 AKT09 AKT14 AKT17 Aarhus Abbasi Accra2010 Afeke Alekseev Alexakis Alhawaj Andersen Antolin Archibald BCHKW Bazett Beliakova Bellingeri Bettencourt Bigelow Blazejewski Boden Bosch Boyle Brin Brochier BrownF Bryden Burgos Caen Carrasco Carter Cattaneo Cheng Chterental Chu Cimasoni Conant Costantino Costello Dalvit Dancso Dema Deng Dolgushev Dror Enriquez Ens Etingof Faifman Fiedler Filmus Freedman Fresse Frohlich Frohman Furusho Gadanidis Gallagher Gaudreau Getzler Godin Gualtieri Gupta Halacheva Henriques Hillman Hirasawa Hoell Hogan Humbert Hurd Itai Izmaylov Jiang JohnsonFreyd KAL Kalka Kamnitzer Karshon Kashaev Katz Kauffman Kazhdan KhesinA Khovanov Kirk Koytcheff Kricker Kuno Kuperberg Lai Lambrechts LazyKnots Le LeD Ledvinka LeeP Leung LiBland LicataT LiuJ Martchenkov Martel Martins Masbaum Massuyeau Matviichuk McKay McLellan Medabalimi Meusburger Mirny MorganS Morrison Morton-Ferguson Moskovich Mracek Munasinghe Murphy Naef Nandakumar Nikolaev Olah Orr Overbay Papakonstantinou Peng Penneys PoleDancing PolyPoly-1605 Polyak Putyra Ramakrishna Rasmussen Raynor Reed Remenik Reshetikhin RobertsonM Roukema Rushworth Samuelson Sazdanovic Schaveling Scherich Schneps Sela Selmani Severa Smirnov Spreer Stein Sternberg SummerHomology2017 TangYC Thimotheus ThurstonD ToledanoLaredo Tsimerman VanDerVeen Vaughan Vergne VideoClub Vo WangH Willwacher Winter Yampolsky Yetter ZeilbergerN Zhang Zibrowius Zung deSilva wClips
Date-Time / Prefix | Comment |
What? A collection of Blackboard Shots (7327, right now, with 191 prefixes), mostly taken
in my office using a ceiling-mounted web camera.
Why? Mostly for my own use and for the use of the other people with whom I share blackboard space. And it is public because the easiest way to make something viewable to a number of people is to make it viewable to the whole world. Oh no! If you found your handwriting here and you don't like it, please let me know and the relevant shot(s) will be removed, no questions asked. How? A ceiling-mounted Logitech QuickCam Pro 9000 web camera is permanently pointed at my blackboard and connected via USB to this web server. The script bbs.php initiates a capture (using luvcview; hit "s" to shoot and "q" to quit), prompts for a file name prefix and a comment, and runs make. The makefile runs MakeDatabase.php (if necessary) to update the ShotDatabase.php. The latter file is used by index.php, which is this page, and also by show.php, used to display individual shots. The makefile also updates bbs.zip, which contains all the above mentioned scripts as well as common.php, showprefix.php, loadnew.php, random.php, the JavaScript actions.js, and the icon bbs.jpg. Finally, $\TeX$-like rendering uses MathJax (automatic on all pages but this one). Exceptions. Some shots are taken by other means and are added manually or using loadnew.php. |
---|---|---|
230604-131414 / Murphy | Lie algebras and the 4CT. | |
230604-131413 / Murphy | $(q+1)$-colourings. | |
230601-123143 / Martchenkov | The Dehn presentation and the Alexander polynomial (2). | |
230426-114235 / LiuJ | PQ Conventions (10). | |
230425-142328 / Martchenkov | The Dehn presentation and the Alexander polynomial. | |
230424-162957 / LiuJ | PQ Conventions (9). | |
230421-134216 / LiuJ | PQ Conventions (8). | |
230420-120115 / LiuJ | PQ Conventions (7). | |
230417-150539 / LiuJ | PQ Conventions (6). | |
230414-114006 / LiuJ | PQ Conventions (5). | |
230414-093729 / LiuJ | PQ Conventions (4). | |
230412-120656 / LiuJ | PQ Conventions (3). | |
230411-112031 / LiuJ | PQ Conventions (2). | |
230406-032007 / Dancso | The 2-pole 2-strand pentagon. | |
230404-021929 / Dancso | Where the hell is div? | |
230402-224734 / Hogan | Solving for $\Phi$. | |
230330-010211 / Dancso | Thoughts on emergent tangles (2). | |
230330-010210 / Dancso | Thoughts on emergent tangles. | |
230329-010028 / Hogan | Computational techniques (2). (more...) | |
230329-010027 / Hogan | Computational techniques. | |
230329-005716 / Hogan | A summary of AKKN (3). | |
230316-004025 / Dancso | Thoughts on emergent knots. | |
230309-191604 / Hogan | A summary of AKKN (2). | |
230309-191603 / Hogan | A summary of AKKN. | |
230301-170218 / LiuJ | PQ Conventions. | |
230228-172204 / Dror | Equivariant linking numbers (2). | |
230228-142644 / Dror | Equivariant linking numbers. | |
230223-125050 / Martchenkov | Matrices and quadratics. | |
230211-100908 / VanDerVeen | Twisted doubles. (more...) | |
230206-092653 / VanDerVeen | Reidemeister torsion (2). | |
230203-072344 / VanDerVeen | Reidemeister torsion. | |
230116-080757 / Bosch | Palindromicity (2). | |
Date-Time / Prefix | Comment | |
230116-080756 / Bosch | Palindromicity. | |
221214-121653 / Afeke | The homology reduced Gassner representation. | |
221214-115337 / Dror | The Gauss diagram formula for $v_2$ is invariant. | |
221213-100013 / Fiedler | Is $V(K\setminus c)$ finite type? (4) | |
221213-094244 / Fiedler | Is $V(K\setminus c)$ finite type? (3) | |
221213-093927 / Fiedler | Is $V(K\setminus c)$ finite type? (2) | |
221213-093920 / Fiedler | Is $V(K\setminus c)$ finite type? | |
221212-165324 / VanDerVeen | Fiedler invariants. | |
221212-121021 / LiuJ | December 2022 marathon (2). | |
221212-112410 / LiuJ | December 2022 marathon. | |
221209-145832 / KAL | Non commutative Gaussian elimination for $S_3$ (2). | |
221207-131543 / Afeke | Intersection numbers in twisted homology (9). | |
221207-124214 / Frohlich | Long rotational virtual knots. | |
221206-140104 / LiuJ | Partial signatures (14). | |
221206-135447 / LiuJ | Partial signatures (13). | |
221202-152320 / KAL | Non commutative Gaussian elimination for $S_3$. | |
221202-150244 / KAL | Gaussian elimination done right. | |
221130-124607 / LiuJ | Partial signatures (12). | |
221130-123024 / Frohlich | Fixing framings. | |
221129-132630 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (7). | |
221129-132625 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (6). | |
221129-132620 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (5). | |
221129-132615 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (4). | |
221129-132609 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (3). | |
221129-132605 / Fiedler | Polynomial invariants which can distinguish the orientations of knots (2). | |
221129-132600 / Fiedler | Polynomial invariants which can distinguish the orientations of knots. | |
221128-125305 / Afeke | Intersection numbers in twisted homology (8). | |
221123-131443 / LiuJ | Partial signatures (11). | |
221123-130442 / LiuJ | Partial signatures (10). | |
221123-124953 / LiuJ | Partial signatures (9). | |
221121-125616 / Afeke | Intersection numbers in twisted homology (7). | |
221118-081503 / Afeke | Intersection numbers in twisted homology (6). | |
Date-Time / Prefix | Comment | |
221109-115137 / Afeke | Intersection numbers in twisted homology (5). | |
221107-115534 / Afeke | Intersection numbers in twisted homology (4). | |
221031-132935 / Afeke | Intersection numbers in twisted homology (3). | |
221031-132930 / Afeke | Intersection numbers in twisted homology (2). | |
221031-132915 / Afeke | Intersection numbers in twisted homology. | |
221028-110613 / Boyle | Finite type invariants of SNACKs (2). | |
221028-110604 / Boyle | Finite type invariants of SNACKs. | |
221021-125136 / KAL | The reduction lemma. | |
221021-122313 / KAL | Homotopies (2). | |
221020-121604 / Jiang | PVB, VB, B, PB. | |
221019-115945 / Afeke | $\Gamma$-calculus (8). | |
221019-113952 / Afeke | $\Gamma$-calculus (7). | |
221014-103631 / Munasinghe | Type B Schur Algebras (5). | |
221014-101429 / Munasinghe | Type B Schur Algebras (4). | |
221014-100250 / Munasinghe | Type B Schur Algebras (3). | |
221014-093556 / Munasinghe | Type B Schur Algebras (2). | |
221014-091646 / Munasinghe | Type B Schur Algebras. | |
221005-124423 / LiuJ | Partial signatures (8). | |
221003-131518 / Afeke | $\Gamma$-calculus (6). | |
221003-125053 / Afeke | $\Gamma$-calculus (5). | |
220930-130635 / KAL | Homotopies. | |
220929-132009 / Afeke | $\Gamma$-calculus (4). | |
220923-130803 / KAL | Frobenius Algebras and TQFTs. | |
220921-122415 / LiuJ | Partial signatures (7). | |
220920-131331 / Afeke | $\Gamma$-calculus (3). | |
220916-130852 / KAL | Listening to Montreal-1306. | |
220908-135316 / Afeke | $\Gamma$-calculus (2). | |
220906-115552 / Afeke | $\Gamma$-calculus. | |
220906-102305 / LiuJ | Partial signatures (6). | |
220826-132145 / KAL | Listening to Newton-1301 (5) | |
220826-130533 / KAL | Listening to Newton-1301 (4) | |
220826-120937 / KAL | Listening to Newton-1301 (3) | |
Date-Time / Prefix | Comment | |
220824-162553 / LiuJ | Partial signatures (5). | |
220823-121143 / Afeke | Unitarity for groupoid representations (5). | |
220817-180228 / LiuJ | Partial signatures (4). | |
220816-113312 / Afeke | Unitarity for groupoid representations (4). | |
220816-111340 / Afeke | Unitarity for groupoid representations (3). | |
220816-105958 / Afeke | Unitarity for groupoid representations (2). | |
220816-104557 / Afeke | Unitarity for groupoid representations. | |
220812-125924 / KAL | Listening to Newton-1301 (2) | |
220812-123644 / KAL | Listening to Newton-1301 | |
220810-100547 / LiuJ | Partial signatures (3). | |
220809-123425 / PoleDancing | The flipper. | |
220809-104022 / Afeke | Gassner as a functor (3). | |
220808-163148 / VanDerVeen | Band Aid marathon. | |
220805-123801 / Frohlich | Co-invariants marathon (3). | |
220805-104100 / Frohlich | Co-invariants marathon (2). | |
220805-092810 / Frohlich | Co-invariants marathon. | |
220804-164222 / LiuJ | Partial signatures (2). | |
220804-155757 / LiuJ | Partial signatures. | |
220804-130344 / Afeke | Gassner as a functor (2). | |
220804-125927 / Afeke | Gassner as a functor. | |
220606-144534 / Afeke | Gassner for a single crossing. | |
220603-150005 / Halacheva | Fast GPV computations (2). | |
220603-143552 / Halacheva | Fast GPV computations. | |
220322-104437 / 2122-257 | Closed -> exact, HW16 Q3 (3). | |
220322-103156 / 2122-257 | Closed -> exact, HW16 Q3 (2). | |
220322-101624 / 2122-257 | Closed -> exact, HW16 Q3. | |
220316-140256 / Afeke | LinAlg issue. | |
220308-105924 / 2122-257 | Fubini for layer-prseringfunctions. | |
220308-102037 / 2122-257 | The adjoint. | |
220308-101424 / 2122-257 | $\theta$. | |
220308-094753 / 2122-257 | Infinitesimal Stokes' Theorem. | |
211215-105403 / LiuJ | Listening to Dancso's talk in Montreal (2). | |
Date-Time / Prefix | Comment | |
211215-102305 / LiuJ | Listening to Dancso's talk in Montreal. | |
211214-122202 / Afeke | Recovering Gassner from $H_1$ (3). | |
211214-115545 / Afeke | Recovering Gassner from $H_1$ (2). | |
211209-140137 / Gupta | The Halting Problem and Godel's Theorem (2). | |
211209-133932 / Gupta | The Halting Problem and Godel's Theorem. | |
211130-172819 / Afeke | Recovering Gassner from $H_1$. | |
211123-165941 / Afeke | On to tangles! (5) | |
211123-164720 / Afeke | On to tangles! (4) | |
211123-161727 / Afeke | On to tangles! (3) | |
211116-164408 / Afeke | On to tangles! (2) | |
211116-163123 / Afeke | On to tangles! | |
211109-145132 / Abbasi | Proof of invariance of Kashaev's signature (6). | |
211109-145131 / Abbasi | Proof of invariance of Kashaev's signature (5). | |
211109-145130 / Abbasi | Proof of invariance of Kashaev's signature (4). | |
211109-145129 / Abbasi | Proof of invariance of Kashaev's signature (3). | |
211109-145128 / Abbasi | Proof of invariance of Kashaev's signature (2). | |
211109-145127 / Abbasi | Proof of invariance of Kashaev's signature. | |
211102-155035 / Afeke | The structure of the cup-product matrix (9). | |
211026-153454 / Afeke | The structure of the cup-product matrix (8). | |
211019-154103 / Afeke | The structure of the cup-product matrix (7). | |
211015-165626 / LiuJ | Bi-algebras, traces. | |
211012-153813 / Afeke | The structure of the cup-product matrix (6). | |
211008-165201 / LiuJ | Group-like elements. | |
211005-153836 / Afeke | The structure of the cup-product matrix (5). | |
210928-160007 / Afeke | The structure of the cup-product matrix (4). | |
210928-154030 / Afeke | The structure of the cup-product matrix (3). | |
210921-160425 / Afeke | The structure of the cup-product matrix (2). | |
210917-170117 / LiuJ | The associated graded of virtual knots. | |
210917-153555 / Frohlich | Traces and rotational virtual tangles. | |
210914-164623 / Afeke | The structure of the cup-product matrix. | |
210910-170725 / LiuJ | Finite generation. | |
210910-161101 / LiuJ | Expansions and UFTIs. | |
Date-Time / Prefix | Comment | |
210728-142257 / KAL | Leonard Afeke on The Gassner Representation of String Links (4). | |
210728-142256 / KAL | Leonard Afeke on The Gassner Representation of String Links (3). | |
210728-142255 / KAL | Leonard Afeke on The Gassner Representation of String Links (2). | |
210728-142254 / KAL | Leonard Afeke on The Gassner Representation of String Links. | |
210715-164340 / TangYC | Sketch of the proof of the planar separator theorem. | |
210701-170112 / Afeke | Completing the Kirk argument (6). | |
210701-170111 / Afeke | Completing the Kirk argument (5). | |
210701-170110 / Afeke | Completing the Kirk argument (4). | |
210630-113540 / Afeke | Supervisory Meeting (2). | |
210630-113539 / Afeke | Supervisory Meeting. | |
210624-165821 / Afeke | Completing the Kirk argument (3). | |
210624-165820 / Afeke | Completing the Kirk argument (2). | |
210624-165819 / Afeke | Completing the Kirk argument. | |
210608-103235 / VanDerVeen | Getting rid of $\hbar$. | |
210604-195914 / Afeke | Computing cup products (4). | |
210528-110135 / Afeke | Computing cup products (3). | |
210528-104400 / Afeke | Computing cup products (2). | |
210517-100249 / Afeke | Computing cup products. | |
210507-092613 / Afeke | More cohomology computations (5). | |
210507-092100 / Afeke | More cohomology computations (4). | |
210507-091439 / Afeke | More cohomology computations (3). | |
210429-152437 / Afeke | More cohomology computations (2). | |
210415-160909 / Afeke | More cohomology computations. | |
210208-164014 / Afeke | Cap products (2). | |
210208-163929 / Afeke | Cap products. | |
201211-153735 / Afeke | The twisted homology of $\partial X$. | |
201105-173823 / Afeke | Reading Kirk's email (2). | |
201105-170312 / Afeke | Reading Kirk's email. | |
201020-161550 / Afeke | Homological representations (2). | |
201020-161519 / Afeke | Homological representations. | |
200811-165033 / Afeke | A split sequence? | |
200729-155915 / Afeke | Crash recovery. | |
Date-Time / Prefix | Comment | |
200724-160451 / Afeke | A crucial statement in Kassel-Turaev (6). | |
200720-154713 / Afeke | A crucial statement in Kassel-Turaev (5). | |
200720-154633 / Afeke | A crucial statement in Kassel-Turaev (4). | |
200719-213611 / VanDerVeen | $t$ and $w$ generate the centre. | |
200717-173256 / VanDerVeen | Abbasi's argument. | |
200717-173027 / Abbasi | A short proof of McCool's theorem (3). | |
200717-173026 / Abbasi | A short proof of McCool's theorem (2). | |
200717-173025 / Abbasi | A short proof of McCool's theorem. | |
200715-155330 / Afeke | A crucial statement in Kassel-Turaev (3). | |
200714-145937 / Frohlich | Proofs of the Weyl commutation relations (2). | |
200714-145936 / Frohlich | Proofs of the Weyl commutation relations. | |
200714-125831 / Dror | Verifying the Heisenberg R-matrix. | |
200713-171423 / Gaudreau | uB injects into vB. | |
200713-160252 / Scherich | Long for w-braids. | |
200710-180818 / VanDerVeen | Traces. | |
200709-173838 / Afeke | A crucial statement in Kassel-Turaev (2). | |
200708-160203 / Frohlich | Are traces trascendental? | |
200703-175526 / VanDerVeen | Zipping quadratics and pairing exterior powers. | |
200703-160731 / Afeke | A crucial statement in Kassel-Turaev. | |
200702-161027 / Frohlich | The Halacheva trace. | |
200630-181150 / Abbasi | Basis conjugating automorphisms are generated by $\sigma_{ij}$ (2). | |
200630-181149 / Abbasi | Basis conjugating automorphisms are generated by $\sigma_{ij}$. | |
200630-181026 / VanDerVeen | Co-invariants, partial traces. | |
200627-114335 / Abbasi | Wormholes on $S^3$ (2). | |
200627-114334 / Abbasi | Wormholes on $S^3$. | |
200626-180156 / VanDerVeen | Mixed-direction homomorphisms. | |
200626-160403 / Frohlich | Partial traces. | |
200626-132922 / Afeke | $H_1({\mathbb R}^2,{\mathbb Z}^2)$. | |
200626-132921 / Afeke | The map $\pi_1\to H_1$ is homomorphic (3). | |
200625-171633 / Munasinghe | Understanding $sl_{2+}^\epsilon$. | |
200621-180015 / VanDerVeen | Heisenberg calculus (2). | |
200621-180014 / VanDerVeen | Heisenberg calculus. | |
Date-Time / Prefix | Comment | |
200621-160318 / Dror | Switching to central variables. | |
200619-171742 / Scherich | Combing braids. | |
200619-171741 / Scherich | Free groups in virtual braid groups. | |
200619-160001 / Abbasi | Towards a proof of McCool's theorem (7). | |
200619-160000 / Abbasi | Towards a proof of McCool's theorem (6). | |
200619-155959 / Abbasi | Towards a proof of McCool's theorem (5). | |
200618-180337 / VanDerVeen | Spinner challenge. | |
200618-175701 / VanDerVeen | Composition for O/U tangles. | |
200618-160602 / Munasinghe | A genus 2 surface. | |
200618-100914 / Meusburger | OU tangles and Hopf words. | |
200617-134608 / Afeke | The map $\pi_1\to H_1$ is homomorphic (2). | |
200616-182321 / Abbasi | Towards a proof of McCool's theorem (4). | |
200616-182320 / Abbasi | Towards a proof of McCool's theorem (3). | |
200616-182319 / Abbasi | Towards a proof of McCool's theorem (2). | |
200616-182318 / Abbasi | Towards a proof of McCool's theorem. | |
200615-194307 / Scherich | The Artin representation. | |
200615-172542 / Scherich | Long's $\rho^+$ construction (2). | |
200615-153139 / Afeke | The map $\pi_1\to H_1$ is homomorphic. | |
200612-182124 / VanDerVeen | Hopf quandles? | |
200612-154042 / Frohlich | Minor identities and Plucker coordinates. | |
200611-161506 / Abbasi | Gauss diagrams, w-braids. | |
200611-155616 / Munasinghe | A representation theory for ${\mathfrak{g}}_\epsilon^+$? | |
200610-183444 / Scherich | Long's $\rho^+$ construction. | |
200610-170726 / Afeke | Back to $\tilde{H}$ (7). | |
200610-170702 / Afeke | Back to $\tilde{H}$ (6). | |
200610-091024 / Dancso | A new(?) approach for solving KV degree by degree. | |
200609-175618 / VanDerVeen | Proof of connectivity. | |
200608-155824 / Afeke | Back to $\tilde{H}$ (5). | |
200603-084840 / Dancso | Expansions for acyclic tangles (3). | |
200603-084839 / Dancso | Expansions for acyclic tangles (2). | |
200601-170137 / Frohlich | Alexander Half Density and palindromicity. | |
200601-153318 / Afeke | Back to $\tilde{H}$ (4). |
See All Shots.