OverviewFilesCommitsIssuesDocsReleasesPeers

opencog-learn commits / dea5ceb

Another step
dea5ceb908bb929151d603d1d404c09a0fe57588
by Linas Vepštas <linasvepstas@gmail.com> · 2026-01-28T22:34:34.000Z

Changed files (1) +230 -2

learn-lang-diary/learn-lang-diary-part-ten-F.lyx +230 -2
……@@ -6851,7 +6851,7 @@ Metric
68516851
68526852\begin_layout Standard
68536853Poincare ball metric with curvature
6854\begin_inset Formula $A$
6854\begin_inset Formula $K=-1/A^{2}$
68556855\end_inset
68566856
68576857,
……@@ -7168,7 +7168,14 @@ The spin connection
71687168
71697169\begin_layout Standard
71707170Let assume the earlier expressions for the spin connection were correct.
7171 Well,
7171 (I wrote the diatribe about Claude,
7172 further below,
7173 first,
7174 and then circled back here to do this by hand.)
7175\end_layout
7176
7177\begin_layout Standard
7178Well,
71727179 lets assume they are not,
71737180 and restart from first principles.
71747181 So
……@@ -7321,6 +7328,203 @@ Finally
73217328\end_inset
73227329
73237330 but this is trivially satisfied by the above results.
7331 I think the above is correct.
7332\end_layout
7333
7334\begin_layout Paragraph*
7335Dirac equation
7336\end_layout
7337
7338\begin_layout Standard
7339So lets repeat.
7340 We have to solve
7341\begin_inset Formula
7342\[
7343\gamma^{a}e_{a}^{\mu}\left(\partial_{\mu}+\Omega_{\mu}\right)\psi=0
7344\]
7345
7346\end_inset
7347
7348with
7349\begin_inset Formula
7350\[
7351\Omega_{\mu}=\frac{1}{4}\omega_{\mu}^{ab}\gamma_{a}\gamma_{b}
7352\]
7353
7354\end_inset
7355
7356subject to the hedgehog boundary conditions applied at
7357\begin_inset Formula $r<1$
7358\end_inset
7359
7360.
7361 We comply trickery from here on out.
7362 I am using Claude to find the tricks.
7363 I'm not verifying them carefully,
7364 they smell correct.
7365\begin_inset Formula
7366\[
7367\left[\gamma_{a},\gamma_{b}\right]=2i\epsilon_{abc}\Sigma^{c}
7368\]
7369
7370\end_inset
7371
7372with
7373\begin_inset Formula
7374\[
7375\Sigma^{c}=\left(\begin{array}{cc}
7376\sigma^{c} & 0\\
73770 & \sigma^{c}
7378\end{array}\right)
7379\]
7380
7381\end_inset
7382
7383so
7384\begin_inset Formula
7385\[
7386\Omega_{\mu}=\frac{i}{4}\epsilon_{abc}\omega_{\mu}^{ab}\Sigma^{c}
7387\]
7388
7389\end_inset
7390
7391Well,
7392 OK,
7393 baby steps.
7394 Next,
7395 we have to hedgehog Ansatz our way through.
7396 Once again,
7397 I think I'll call it quits here,
7398 for now.
7399 I've actually asked Claude to take many more steps from here.
7400 I don't trust it's results,
7401 so I am not copying them here,
7402 but so far,
7403 we're having some amount of fun.
7404 The vibes are OK,
7405 so far.
7406\end_layout
7407
7408\begin_layout Paragraph*
7409Claude code
7410\end_layout
7411
7412\begin_layout Standard
7413Err,
7414 well I will sketch what Claude is telling me.
7415 It smells OK.
7416 It might have errors.
7417 But the overall picture is not insane.
7418 I gather that someone has published these details,
7419 and Claude trained on them,
7420 and is remembering them.
7421 Here goes.
7422\end_layout
7423
7424\begin_layout Standard
7425One trick is to absorb the spin connection into an angular momentum term.
7426 I won't write that down.
7427\end_layout
7428
7429\begin_layout Standard
7430Next trick is to write
7431\begin_inset Formula
7432\[
7433\psi=\left(\begin{array}{c}
7434\psi_{+}\\
7435\psi_{-}
7436\end{array}\right)
7437\]
7438
7439\end_inset
7440
7441with
7442\begin_inset Formula
7443\begin{align*}
7444E\psi_{+} & =-i\vec{\sigma}\cdot\vec{D}\psi_{-}+m\psi_{+}\\
7445E\psi_{-} & =-i\vec{\sigma}\cdot\vec{D}\psi_{+}-m\psi_{-}
7446\end{align*}
7447
7448\end_inset
7449
7450where
7451\begin_inset Formula
7452\begin{align*}
7453\vec{\sigma}\cdot\vec{D} & =\frac{\vec{\sigma}\cdot\hat{r}}{\lambda}\left(\partial_{r}+\frac{1}{1-r^{2}}+\frac{1+r^{2}}{1-r^{2}}\frac{\left(\vec{\sigma}\cdot\hat{r}\right)\left(\vec{\sigma}\cdot\vec{L}\right)}{r}\right)\\
7454 & =\frac{\vec{\sigma}\cdot\hat{r}}{\lambda}\left(\partial_{r}-\frac{r}{1-r^{2}}+\frac{1+r^{2}}{1-r^{2}}\left[\frac{1+\left(\vec{\sigma}\cdot\hat{r}\right)\left(\vec{\sigma}\cdot\vec{L}\right)}{r}\right]\right)\\
7455 & =\frac{\vec{\sigma}\cdot\hat{r}}{2A}\left(\left(1-r^{2}\right)\partial_{r}+1+\left(1+r^{2}\right)\frac{\left(\vec{\sigma}\cdot\hat{r}\right)\left(\vec{\sigma}\cdot\vec{L}\right)}{r}\right)
7456\end{align*}
7457
7458\end_inset
7459
7460and the flat–space version would have been
7461\begin_inset Formula
7462\[
7463\vec{\sigma}\cdot\vec{\nabla}=\vec{\sigma}\cdot\hat{r}\left(\partial_{r}+\frac{1+\left(\vec{\sigma}\cdot\hat{r}\right)\left(\vec{\sigma}\cdot\vec{L}\right)}{r}\right)
7464\]
7465
7466\end_inset
7467
7468To regain flat space
7469\begin_inset Formula $K=0$
7470\end_inset
7471
7472 in the limit,
7473 set
7474\begin_inset Formula $K\to0$
7475\end_inset
7476
7477 which means
7478\begin_inset Formula $A\to\infty$
7479\end_inset
7480
7481 and rescale
7482\begin_inset Formula $r=R/2A$
7483\end_inset
7484
7485 with
7486\begin_inset Formula $R$
7487\end_inset
7488
7489 held fixed.
7490 This means all factors
7491\begin_inset Formula $r^{2}\to0$
7492\end_inset
7493
7494 and all the rest works out as expected.
7495 Good.
7496\end_layout
7497
7498\begin_layout Standard
7499The Hedgehog Ansatz is
7500\begin_inset Formula
7501\[
7502\psi_{+}=u\chi\qquad\psi_{-}=iv\left(\vec{\sigma}\cdot\hat{r}\right)\chi
7503\]
7504
7505\end_inset
7506
7507with
7508\begin_inset Formula $\left(\vec{\sigma}+\vec{\tau}\right)\chi=0$
7509\end_inset
7510
7511.
7512 So
7513\begin_inset Formula $\left(\vec{\sigma}\cdot\hat{r}\right)^{2}=1$
7514\end_inset
7515
7516 and Claude claims
7517\begin_inset Formula $\left(\vec{\sigma}\cdot\hat{L}\right)^{2}\chi=-\chi$
7518\end_inset
7519
7520 for the hedgehog.
7521 Is this right?
7522 Well,
7523 maybe,
7524 I guess.
7525 Who knows.
7526 Assuming it is,
7527 the radial equations become
73247528\end_layout
73257529
73267530\begin_layout Paragraph*
……@@ -7502,6 +7706,30 @@ But for now,
75027706 The End.
75037707\end_layout
75047708
7709\begin_layout Standard
7710Or not.
7711 It's not that bad.
7712 I gave in to the vibe,
7713 and pushing further does not look all that bad.
7714 The formulas look OK–ish.
7715 I am copying them into place above,
7716 without really checking.
7717 I am guessing that this is previously published material and Claude is regurgitating it correctly.
7718 I feel like this guy and this girl says
7719\begin_inset Quotes eld
7720\end_inset
7721
7722this will feel good
7723\begin_inset Quotes erd
7724\end_inset
7725
7726 and she goes down on me,
7727 and what's there to complain about?
7728 So I'll share some consensual hallucinations with Claude for just a bit longer,
7729 and see if it's OK.
7730 So scroll back up for the results.
7731\end_layout
7732
75057733\begin_layout Subsection*
7506773428 January 2026
75077735\end_layout