The topological 4-genus of a knot is the minimum genus of a topological, locally flat surface embedded in the 4-ball with boundary the knot. Bounds arise from the p-signatures and, to obstruct being of 4-genus 0 (slice), the Alexander polynomial. The additional bounds that arise in the smooth case don't apply here. For instance, there are knots of Alexander polynomial 1 that are not smoothly slice, but are topologically slice by Freedman's work.

8_{16}, 8_{18}, 9_{17}, 9_{31}, 9_{32}, 9_{40}, 9_{47}

Ref. [5]

9_{48}, 10_{117}, 10_{144}

Ref. [3]

10_{51}

Selahi Durusoy has found a single crossing change (in the given diagram) that converts 10_{51} into 8_{8},
which is slice.

10_{54}, 10_{70}, 10_{97}, 10_{148}, 10_{151}

Ref. [7]

10_{{139, 145, 161}}, 11a_{211}, 11n_{{9, 77, 183}}, 12a_{153 255, 1414, 534, 542, 624, 636, 719,
1118}, 12n_{59, 91, 105, 110, 120, 136, 148, 175, 187, 199, 207, 217, 220, 228, 239, 242, 328, 329, 366, 374, 402, 404, 417,
426, 472, 512, 518, 528, 574, 575, 591, 594, 640, 647, 660, 679, 680, 688, 689, 691, 692, 693, 694, 696,
725, 801, 850, 851, 888}.

Mark Brittenham has computed new information regarding these knots. Some details are contained in
excerpts from his letter concerning the unknotting number: Mark Brittenham's notes.

10_{161}

Ref. [8], [6]

11a_{28}, 11a_{35}, 11a_{36}, 11a_{96}, 11a_{164}

Ribbon Knot: Personal communication with Christoph Lamm.

11a_{61}, 11a_{304}, 11n_{31}

Alexander Stoimenow found a genus 1 concordance to an Alexander polynomial 1 knot, and thus the topological 4-genus
is at most 1.

11a_{316}, 11a_{326}, 11n_{4}

Ribbon Knot: Personal communication with Alexander Stoimenow.

11n_{80}, 12a_{187, 230, 0317, 450, 570, 908, 1185, 1189, 1208}, 12a_{787}, 12n_{52, 63, 225, 542, 558,
665, 886} 12n_{{269, 505, 598, 602, 756}}, 12n_{276}

Ref. [4]

12a_{3, 54, 77, 100, 173, 183, 189, 211, 221, 245, 258, 279, 348, 348, 377, 425, 427, 435, 447, 456, 458, 464, 473,
477, 484, 484, 606, 646, 667, 715, 786, 819, 879, 887, 975, 979, 1011, 1019, 1019, 1029, 1034, 1083, 1087, 1105, 1105,
1119, 1202, 1202, 1225, 1225, 1269, 1277, 1283}

12n_{4, 19, 23, 24, 43, 48, 49, 51, 56, 57, 62, 66, 87, 106, 145, 170, 214, 256, 257, 268, 279, 288, 309, 312,
313, 318, 360, 380, 393, 394, 397, 399, 414, 420, 430, 440, 462, 501, 504, 553, 556, 582, 605, 636, 657, 670, 676, 702,
706, 708, 721, 768, 782, 802, 817, 838, 870, 876}

Alexander Stoimenow did a computer search to identify slice knots of 12 crossings and found these
(smooth) ribbon knots.

genus 1: 12a_{{441}}, 12n_{{433,520,577,719}}

genus 2: 12n_{{624}}

Alexander Stoimenow did a computer search to identify knots of 12 crossings that have genus 1 or genus 2
concordances to knots of Alexander polynomial 1, and thus are of topological genus 1 or 2. That search found these examples.

12n_{113}, 12n_{190}, 12n_{233}, 12n_{345}, 12n_{707}, 12n_{822}, and
12n_{829}

Ref. [1]

12n_{321} (1), 12n_{411} (1), 12n_{519} (1), 12n_{750} (2), 12n_{830} (2), and
12n_{293} (1)

Ref. [2]

Duncan McCoy used a computer search to find low genus surfaces in the four-ball bounded by knots and used the results to determine the smooth four-genus of over 600 11 and 12 crossing knots. This also determined the topological four-genus for many of these knots. See smooth four-genus references and [4] for more details.

12a_{631}

Axel Seeliger proved that this knot is slice. Diagram

[1] Boileau, M., Boyer, S., and Gordon, C., "Branched covers of quasipositive links and L-spaces," Arxiv preprint.

[2] Feller, P., "The degree of the Alexander polynomial is an upper bound for the topological slice genus," Arxiv preprint.

[3] Fujino, Y., Miyazawa, Y., and Nakajima, K., "H(n)-unknotting nubmer of a knot," Reports of knots and low-dimensional manifolds (1997), 72-85.

[4] Lewark, L. and McCoy, D., "On calculating the slice genera of 11- and 12-crossing knots," Arxiv preprint.

[5] Murakami, H. and Nakanishi, Y., "Triple points and knot cobordism," Kobe J. Math, v 1. (1984), 1-16.

[6] Rasmussen, J., "Khovanov homology and the slice genus," Arxiv preprint.

[7] Shibuya, T., *Memoirs of the Osaka Institute of Technology*, Vol 45 (2000), 1-10.

[8] Tanaka, T., "Unknotting numbers of quasipositive knots," Top. Appl 88 (1998), 239-246.