User Tim

26 votes

4 answers

7k views

Is there a mathematical reason for the Lagrangian to be Lorentz invariant?

asked Dec 1, 2014 at 15:52

20 votes

2 answers

3k views

Vector spaces for the irreducible representations of the Lorentz Group

asked Nov 29, 2014 at 12:05

18 votes

3 answers

2k views

Why is the "actual" gauge group of the standard model $SU(3) \times SU(2) \times U(1) /N$?

asked Apr 16, 2015 at 18:00

17 votes

1 answer

2k views

Why is the strong CP term $ \theta \frac{g^2}{32 \pi^2} G_{\mu \nu}^a \tilde{G}^{a, \mu \nu}$ never considered for $SU(2)$ or $U(1)$ interactions?

asked Apr 16, 2015 at 7:29

15 votes

1 answer

2k views

Do electrons oscillate into muons just like electron-neutrinos into muon-neutrinos?

asked Apr 15, 2015 at 7:29

15 votes

1 answer

2k views

Why do we require quantum fields to vanish at infinity?

asked Jan 23, 2015 at 8:59

11 votes

1 answer

2k views

How can we measure chirality in experiments?

asked Jan 24, 2015 at 8:54

9 votes

2 answers

468 views

If $v_{a \dot{b}}$ transforms like a four-vector, what does $v_{a}^{\dot{b}}$ describe?

asked Jan 18, 2015 at 14:47

9 votes

2 answers

2k views

Why does the minus sign in the Minkowski metric mean that nothing can move backwards in time?

asked Apr 3, 2015 at 15:58

9 votes

1 answer

724 views

Where does the $U(1)$ factor come from in GUT symmetry breaking?

asked Apr 16, 2015 at 20:22

5 votes

2 answers

1k views

Under what representation do the Christoffel symbols transform?

asked Apr 14, 2015 at 11:56

5 votes

2 answers

1k views

Why is the $(\frac{1}{2},\frac{1}{2})$ representation of the Lorentz group realized as the vector space of Hermitian $2\times 2$ matrices?

asked Jan 22, 2015 at 8:16

4 votes

1 answer

457 views

The Einstein-Cartan equation as the "living heart of gravity"?

asked Apr 8, 2015 at 8:30

4 votes

1 answer

1k views

Are there any good books about Grand Unified Theories?

asked Apr 18, 2015 at 16:15

4 votes

2 answers

847 views

Is $SU(2)$ really broken by the Higgs VEV or just hidden?

asked Apr 19, 2015 at 9:29

1 vote

2 answers

2k views

The Lie algebra of the Lorentz group is $su(2) \oplus su(2)$. Is there a similar relation for the algebra of the Poincare group?

asked Apr 19, 2015 at 15:08

1 vote

1 answer

184 views

What is the current state of axion research theoretically?

asked Apr 15, 2015 at 6:27

1 vote

0 answers

43 views

How can family symmetries explain the 3 generations and their mixing?

asked Apr 15, 2015 at 12:52

1 vote

0 answers

62 views

Name for the transformation into an accelerated frame?

asked Apr 3, 2015 at 10:15

1 vote

1 answer

431 views

Covariant formulation of physical equations?

asked Apr 3, 2015 at 14:25

1 vote

0 answers

71 views

How to get from $E_8 \rightarrow E_7 \rightarrow E_6 \rightarrow ...$

asked Apr 16, 2015 at 8:37

Stack Exchange Network

21 Questions

Is there a mathematical reason for the Lagrangian to be Lorentz invariant?

Vector spaces for the irreducible representations of the Lorentz Group

Why is the "actual" gauge group of the standard model $SU(3) \times SU(2) \times U(1) /N$?

Why is the strong CP term $ \theta \frac{g^2}{32 \pi^2} G_{\mu \nu}^a \tilde{G}^{a, \mu \nu}$ never considered for $SU(2)$ or $U(1)$ interactions?

Do electrons oscillate into muons just like electron-neutrinos into muon-neutrinos?

Why do we require quantum fields to vanish at infinity?

How can we measure chirality in experiments?

If $v_{a \dot{b}}$ transforms like a four-vector, what does $v_{a}^{\dot{b}}$ describe?

Why does the minus sign in the Minkowski metric mean that nothing can move backwards in time?

Where does the $U(1)$ factor come from in GUT symmetry breaking?

Under what representation do the Christoffel symbols transform?

Why is the $(\frac{1}{2},\frac{1}{2})$ representation of the Lorentz group realized as the vector space of Hermitian $2\times 2$ matrices?

The Einstein-Cartan equation as the "living heart of gravity"?

Are there any good books about Grand Unified Theories?

Is $SU(2)$ really broken by the Higgs VEV or just hidden?

The Lie algebra of the Lorentz group is $su(2) \oplus su(2)$. Is there a similar relation for the algebra of the Poincare group?

What is the current state of axion research theoretically?

How can family symmetries explain the 3 generations and their mixing?

Name for the transformation into an accelerated frame?

Covariant formulation of physical equations?

How to get from $E_8 \rightarrow E_7 \rightarrow E_6 \rightarrow ...$