Skip to main content

New answers tagged

10 votes

Do the surreal numbers enjoy the transfer principle in ZFC?

A partial answer to the focused question: it's not provable in ZFC that there is an OD class $\mathbb{Z}^*$ such that $(\mathbb{R}, +, \cdot, \mathbb{Z}) \equiv (\mathrm{No}, +, \cdot, \mathbb{Z}^*).$ ...
Elliot Glazer's user avatar
16 votes

Do the surreal numbers enjoy the transfer principle in ZFC?

In $\mathsf{ZFC}$ if any two proper class models of the theory of an infinite set are isomorphic, then global choice holds. This is because $V$ and $\mathrm{Ord}$ are both models of this theory and an ...
James E Hanson's user avatar
9 votes

Are periodic functions such as sine and cosine defined on surreal numbers?

Since the surreal numbers form a saturated real-closed field, it follows that they serve as a (proper class) version of the hyperreal numbers, including the transfer principle. This means that ...
Joel David Hamkins's user avatar
0 votes

In hyperreal field, can ln(ε) and ln(ω) be expressed as infinite sums?

I will propose an answer my question. Please let me know if I have spoken accurately. Within the hyperreal field (that is, the most traditional hyperreal field as described by some of the original ...
euclidub's user avatar
8 votes

In hyperreal field, can ln(ε) and ln(ω) be expressed as infinite sums?

To help avoid any misunderstanding that may arise for readers of this question, let me say that when understood in the usual sense, there are no nontrivial convergent sequences or series at all in the ...
Joel David Hamkins's user avatar
3 votes

In hyperreal field, can ln(ε) and ln(ω) be expressed as infinite sums?

For positive $\epsilon$, the expression $\ln \epsilon$ will be equal to its power series at $x=1$ (in the $\delta, N$ sense). To help avoid any misunderstanding that may arise for readers of this ...
Mikhail Katz's user avatar
  • 16.6k

Top 50 recent answers are included