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Testing a claim that phistar=R REVIEWED
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Dated March 2016, with a note added 5.17.16 and the title line dated 3.17.17, these working notes belong to Phil's Chapter 10 development of the wedge/tensor document. They map the Section 7.19 data onto "Picture F" with t-space and x-space basis vectors, then test φ*T = RT in two versions. The first, with the xui basis, fails; the second, with the xei basis, succeeds, and Phil concludes φ* is just RT.
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Testing the claim that φ* = R PhL 3.17.17
5.17.16: two items here
(1) working with the messy t-space to x-space notations like xu . I decided not to show any of this but to relegate it to Appendix E.
(2) at this point I am still thinking of φ* as a synonym for R. But later I made two changes to this idea. The first is that R became Dirac operator R, and the second that φ* became a function not an operator. I just had a wrong threading, that's all! I like the final presentation in wedge doc Section 10.7.
This is taken from "paradox v1 3_14_16.doc".
3/19/16. Preliminary. I want here to "map" all my new tensor-doc Section 7.19 facts to Picture F.
For example, in Section 7.19 I have this major data:
(un)i = ui un = <ui | un > = gin = u'i u'n = < u'i | u'n >
(en)i = ui en = <ui | en > = Sin = Rni
(en')i = e'i e'n = < e'i | e'n > = g'in = ei en = <ei | en >
(un')i = e'i u'n = <e'i | u'n> = Rin = Sni (7.19.12)
<en | S | e'i> = <e'i | R | en> = g'in
<en | S | u'i> = <u'i | R | en> = Sin = Rni
<un | S | e'i> = <e'i | R | un> = Rin = Sni
<un | S | u'i> = <u'i | R | un> = gin . (7.19.19)
The forward rules are these:
e' → xe
e → te
u → tu
u' → xu
So I will copy the above block, make it red, do edits making things black
(tun)i = tui tun = <tui | tun > = gin = u'i u'n = < u'i | u'n >
(ten)i = tui ten = <tui | ten > = Sin = Rni
(xen)i = xei xen = < xei | xen > = g'in = tei ten = <tei | ten >
(xun)i = xei xun = <xei | xun> = Rin = Sni (7.19.12)
<ten | S | xei> = <xei | R | ten> = g'in
<ten | S | xui> = <xui | R | ten> = Sin = Rni
<tun | S | xei> = <xei | R | tun> = Rin = Sni
<tun | S | xui> = <xui | R | tun> = gin . (7.19.19)
Here then is the resulting data block:
(tun)i = tui tun = <tui | tun > = gin = u'i u'n = < u'i | u'n >
(ten)i = tui ten = <tui | ten > = Sin = Rni
(xen)i = xei xen = < xei | xen > = g'in = tei ten = <tei | ten >
(xun)i = xei xun = <xei | xun> = Rin = Sni (7.19.12)
<ten | S | xei> = <xei | R | ten> = g'in
<ten | S | xui> = <xui | R | ten> = Sin = Rni
<tun | S | xei> = <xei | R | tun> = Rin = Sni
<tun | S | xui> = <xui | R | tun> = gin . (7.19.19)
2. Want to test the following claim: [ try this in all-Dirac notation sep doc]
(a) φ*T = RT and φ* = R [assume]
for the pullback matrix. I think this is true from two sources:
I derive it in "is phi star symmetric v2"
It comes out at the end in "Section 10_6 v2".
Now consider my definition of φ*T as stated in Ch 10 v 3
(b) φ*T(xui) ≡ Σj=1n Rij (tuj) i = 1..m [ok] (10.6.9)
I claim that in Picture F' we have
(7.19.24) (10.6.2,3)
Rij = <e'i | R | uj> → <xei| R | tuj> // checked: <xei | R | tun> = Rin so OK
<xei | R | tuj> = Rij
So write (b) in all-Dirac notation:
φ*T | xui> = Σj=1n <xei| R | tuj> |tuj> = Σj=1n Rij |tuj>
We are trying to compare this to
RT | xui> = Σj=1n | tuj><tuj| RT | xui> = Σj=1n <tuj | RT | xui> | tuj>
= Σj=1n <xui| R |tuj > | tuj> = Σj=1n gij | tuj> = | tui>
where I compute
<xui | R | tun> = gin
<xui | R | tuj> = gij .
Since RT = R-1, this result makes perfect sense.
So here is what I have so far
φ*T | xui> = Rij |tuj> = linear combination of basis vectors in t-space
RT | xui> = | tui> [ improved results 3.19.16 ]
These are NOT the same, case closed. So the hunch that maybe φ*T = RT is wrong.
We also know that
(xui) = R(tui) or |xui> = |R(tui)> = R |tui>
and |tui> = R-1|xui> = RT |xui>
then can write first line as
φ*T | xui> = Rij RT |xuj>
or
Rφ*T | xui> = Rij |xuj>
which does not seem to add much. Now transpose the two equations above
< xui| φ* = Rij <tuj|
< xui| R = < tui|
Close this with a t-space vector v to get
< xui| φ*| v> = Rij <tuj|v> = Rijvj = [Rv]i (*)
< xui| R | v> = < tui|v> = vi
What destination am I seeking here? Since < xui| is a special case of <αx|, and since this is the goal
<αx | φ*| vn,vn...vn> = <αx | Rvn,Rvn...Rvn> .
or
<αx | φ*| v> = <αx | Rv> .
so the goal is
<xui | φ*| v> = <xui | Rv> . (**)
Statement of my Problem at 1 PM 3.19.16: How do you get from (*) to (**) ?
Plan A: I now have a sandbox Section 10_6 v4.doc in which I make a different assumption about what φ* does. I will try that here and see what happens:
Plan A 2. Want to test the following claim: [ try this in all-Dirac notation sep doc]
(a) φ*T = RT and φ* = R [assume]
for the pullback matrix. I think this is true from two sources:
I derive it in "is phi star symmetric v2"
It comes out at the end in "Section 10_6 v2".
Now consider my definition of φ*T as stated in Ch 10 v 3
(b) φ*T(xei) ≡ Σj=1n Rij (tuj) i = 1..m [ok] (10.6.9)
I claim that in Picture F' we have
(7.19.24) (10.6.2,3)
Rij = <e'i | R | uj> → <xei| R | tuj> // checked: <xei | R | tun> = Rin so OK
<xei | R | tuj> = Rij
So write (b) in all-Dirac notation:
φ*T | xei> = Σj=1n <xei| R | tuj> |tuj> = Σj=1n Rij |tuj>
We are trying to compare this to
RT | xei> = Σj=1n | tuj><tuj| RT | xei> = Σj=1n <tuj | RT | xei> | tuj>
= Σj=1n <xei| R |tuj > | tuj> = Σj=1n Rij | tuj>
where I compute
<xei | R | tun> = Rin
<xei | R | tuj> = Rij .
[ Since RT = R-1, this result makes perfect sense. not relevant now ]
So here is what I have so far
φ*T | xei> = Σj=1n Rij |tuj> = linear combination of basis vectors in t-space
RT | xei> = Σj=1n Rij | tuj> [ improved results 3.19.16 3 PM ]
These ARE the same, case closed. So the hunch that maybe φ*T = RT is right!.
So this looks much better.
Remember that
(xui) = R(tui)
so R maps the t-space basis vectors into the tangent base vectors for TxM in x-space. We can invert that to get
(tui) = R-1(xui) = RT(xui)
so RT does just the reverse. So φ* is just RT and it is a tempest in a teapot. There is no strange mysterious mapping. I guess I will now try a complete rewrite of Ch 10_6 with this new approach and see if it flies.
Take a break at 3 PM.