User Keshav Srinivasan

106 votes

2 answers

32k views

What is the definition of the function T used in Atiyah's attempted proof of the Riemann Hypothesis?

asked Sep 24, 2018 at 4:29

39 votes

4 answers

4k views

Illustrating Edward Nelson's Worldview with Nonstandard Models of Arithmetic

asked Sep 20, 2013 at 5:10

37 votes

3 answers

3k views

What is the structure preserved by strong equivalence of metrics?

asked Dec 30, 2018 at 1:10

32 votes

1 answer

2k views

Is it still an open problem whether $\mathbb{R}^\omega$ is normal in the box topology?

asked Nov 8, 2018 at 21:45

26 votes

4 answers

5k views

Can $L^{2}$ be represented as a space of functions (not equivalence classes)?

asked Dec 31, 2011 at 23:52

22 votes

1 answer

2k views

Can we axiomatize Omnific Integers without the Surreal Number system?

asked Aug 11, 2011 at 15:23

17 votes

3 answers

491 views

What alternatives are there to the binomial poset theory of generating function families?

asked May 8, 2021 at 21:53

16 votes

1 answer

2k views

Fulfilling Pythagoras' Dream using Nonstandard Models of Arithmetic and/or Surreal Numbers

asked Feb 6, 2011 at 15:24

16 votes

2 answers

1k views

Is it known how the Sigma Algebra generated by Jordan measurable sets compares to universally measurable sets and analytic sets?

asked Nov 11, 2018 at 3:36

14 votes

4 answers

2k views

Is there an algorithm for the genus of a knot?

asked Sep 21, 2022 at 4:49

13 votes

1 answer

458 views

Which knot invariants have no known diagram-independent descriptions?

asked Sep 11, 2019 at 7:54

13 votes

1 answer

1k views

What is the state of research on finding all prime knots with 17 crossings?

asked Sep 11, 2019 at 19:17

13 votes

0 answers

404 views

Is it an open problem whether fast-growing hierarchies can be defined without fundamental sequences?

asked Nov 13, 2019 at 6:31

11 votes

3 answers

626 views

Has the Ramified Theory of Types been applied to NBG?

asked Dec 8, 2013 at 5:18

11 votes

1 answer

379 views

What is the Turing degree of the monadic theory of the real line?

asked Mar 4, 2021 at 7:02

10 votes

1 answer

392 views

Is $\mathbb{Z}$ universally definable in any number fields other than $\mathbb{Q}$?

asked Jan 24, 2021 at 6:19

10 votes

1 answer

828 views

What is the theory of the random poset?

asked Mar 30, 2021 at 6:05

9 votes

0 answers

940 views

Has anyone pursued Frege's idea of numbers as second-order concepts?

asked Sep 15, 2013 at 3:00

8 votes

3 answers

2k views

Does the Feferman-Schutte analysis give a precise characterization of Predicative Second-Order Arithmetic?

asked Sep 26, 2013 at 5:45

8 votes

1 answer

375 views

What subsystem of second-order arithmetic is needed for the recursion theorem?

asked Jul 21, 2020 at 9:48

8 votes

1 answer

443 views

What subsystem of third order arithmetic proves the real numbers are Dedekind complete?

asked Jul 22, 2020 at 14:02

8 votes

3 answers

1k views

For what sets does the Lebesgue Differentiation Theorem hold in one dimension?

asked Nov 19, 2018 at 7:39

8 votes

1 answer

247 views

What is the lowest complexity definition of $\mathbb{Z}$ in an infinite extension of $\mathbb{Q}$

asked Feb 3, 2021 at 23:22

7 votes

0 answers

357 views

When do two knots have isomorphic fundamental bikeis?

asked Dec 10, 2019 at 13:48

6 votes

1 answer

512 views

What is the Galois group of one ultrapower over another ultrapower?

asked Jan 24, 2021 at 21:47

6 votes

1 answer

225 views

Does $\text{ACA}_0$ + True Arithmetic prove the well-foundedness of every recursive ordinal?

asked Dec 23, 2022 at 6:50

5 votes

1 answer

244 views

Does there always exist a categorical extension of $ZFC_2$ with no set models?

asked Nov 27, 2021 at 19:45

5 votes

1 answer

400 views

Is there a complete characterization of ordered fields without definable proper subfields?

asked Dec 19, 2020 at 2:02

5 votes

1 answer

848 views

Why is adopting Russell's Axiom of Reducibility as strong as eliminating the Ramified Hierarchy?

asked Jan 15, 2014 at 4:04

5 votes

4 answers

1k views

How can you formalize the metamathematics conventionally used to state Godel’s theorem?

asked Jul 29, 2018 at 6:28

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56 Questions

What is the definition of the function T used in Atiyah's attempted proof of the Riemann Hypothesis?

Illustrating Edward Nelson's Worldview with Nonstandard Models of Arithmetic

What is the structure preserved by strong equivalence of metrics?

Is it still an open problem whether $\mathbb{R}^\omega$ is normal in the box topology?

Can $L^{2}$ be represented as a space of functions (not equivalence classes)?

Can we axiomatize Omnific Integers without the Surreal Number system?

What alternatives are there to the binomial poset theory of generating function families?

Fulfilling Pythagoras' Dream using Nonstandard Models of Arithmetic and/or Surreal Numbers

Is it known how the Sigma Algebra generated by Jordan measurable sets compares to universally measurable sets and analytic sets?

Is there an algorithm for the genus of a knot?

Which knot invariants have no known diagram-independent descriptions?

What is the state of research on finding all prime knots with 17 crossings?

Is it an open problem whether fast-growing hierarchies can be defined without fundamental sequences?

Has the Ramified Theory of Types been applied to NBG?

What is the Turing degree of the monadic theory of the real line?

Is $\mathbb{Z}$ universally definable in any number fields other than $\mathbb{Q}$?

What is the theory of the random poset?

Has anyone pursued Frege's idea of numbers as second-order concepts?

Does the Feferman-Schutte analysis give a precise characterization of Predicative Second-Order Arithmetic?

What subsystem of second-order arithmetic is needed for the recursion theorem?

What subsystem of third order arithmetic proves the real numbers are Dedekind complete?

For what sets does the Lebesgue Differentiation Theorem hold in one dimension?

What is the lowest complexity definition of $\mathbb{Z}$ in an infinite extension of $\mathbb{Q}$

When do two knots have isomorphic fundamental bikeis?

What is the Galois group of one ultrapower over another ultrapower?

Does $\text{ACA}_0$ + True Arithmetic prove the well-foundedness of every recursive ordinal?

Does there always exist a categorical extension of $ZFC_2$ with no set models?

Is there a complete characterization of ordered fields without definable proper subfields?

Why is adopting Russell's Axiom of Reducibility as strong as eliminating the Ramified Hierarchy?

How can you formalize the metamathematics conventionally used to state Godel’s theorem?