Talk:CPT symmetry

Hermitian Hamiltonian

I thought all Hamiltonian were hermitian. Paranoidhuman (talk) 21:12, 20 June 2016 (UTC)

Antimatter

The following statement is not quite correct:

with all of matter replaced by anti-matter (corresponding to a charge inversion),

Antimatter requires a parity inversion as well, due to the handedness of neutrinos and antineutrinos. --Christopher Thomas 20:56, 9 Jun 2005 (UTC)

This isn't really true; the operation of charge conjugation is simply as stated in the article. Charge conjugation is not a symmetry of the universe exactly because neutrinos and antineutrinos are only observed with one handedness and not the other, but this does not prevent a formal use of a charge-conjugation operation. Yggdrasil 07:30, 26 February 2006 (UTC)

My point is that replacing all matter with antimatter does not perform a C transform, as stated in the article, as it would require changing the spin of converted neutrinos, among other things. The symmetry being discussed is charge inversion; just leave it as stating charge inversion, without the misleading example.--Christopher Thomas 08:23, 26 February 2006 (UTC)

What is the conservation law corresponding to CPT symmetry?

What is the conserved quantity corresponding to CPT symmetry? Isn't it the case that such a quantity must exist by Noether's theorem? If the answer to this question is other than "nothing," please edit the entry accordingly. 132.181.160.42 (talk) 05:13, 26 August 2009 (UTC)

It can be shown that CPT symmetry is equivalent to symmetry under the Lorentz transformation. If you want to know what conserved quantity corresponds to Lorentz symmetry, the answer is in this link. 69.248.139.9 (talk) 19:20, 21 November 2010 (UTC)

Noether's theorem only applies to continuous symmetries. CPT is a discrete symmetry, therefore Noether's theorem doesn't apply to it. Previous comment is wrong and confusing. —Keenan Pepper 05:53, 22 November 2010 (UTC)

Mirror Image

The statement "The CPT transformation turns our universe into its "mirror image" and vice versa." is not true. Although the CPT symmetry causes the particle and antiparticle to reflect in their inertial frame of reference. Movement of that frame of reference with respect to a local center of mass frame would cause the complementary universe to have some differences when reflected in the "local" center of mass frame of reference. The complementary universe would only be a mirror image if all the particle-antiparticle pairs performed their reflections at the same instant of time and in the same place. 198.203.213.6 (talk) 18:42, 18 December 2015 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 09:45, 10 November 2007 (UTC)

Greenberg's proof was disputed - what is current opinion

Article says "In 2002 Oscar Greenberg proved that CPT violation implies the breaking of Lorentz symmetry.[6] This implies that any study of CPT violation includes also Lorentz violation. However, Chaichian et al later disputed the validity of Greenberg's result.[7]"(2011) - So (since 2011) do Greenberg and others now accept the 2002 proof was invalid ? - Rod57 (talk) 07:53, 10 September 2016 (UTC)