## Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars

### NUPAC Seminar

#### Presented by Kevin Cahill, UNM

Intrinsically broken symmetries of general relativity, tensor Yang-Mills fields and dark matter

The action of general relativity with fermions has two independent symmetries: general-coordinate invariance and local Lorentz invariance. These local symmetries are intrinsically broken by the nonzero average values of the tetrads which reduce the independent symmetries of general-coordinate invariance and local gauge invariance to a single exact symmetry — local Lorentz invariance.

In standard general relativity, local Lorentz invariance is implemented by the spin connection. Here local Lorentz invariance is implemented by spin-two gauge fields and a real vector boson which must be timelike in order for the gauge-field action to be bounded below. The vector boson is neutral and massive, and contributes to dark matter.

The invariances of general relativity with fermions are extended from general-coordinate invariance and local Lorentz invariance to general-coordinate invariance and local U(2,2) invariance.

If the contracted squares of the covariant derivatives of the tetrads multiplied by the square of a mass M are added to the action, then in the limit M → ∞ the equation of motion of the spin- two gauge fields is the vanishing of the covariant derivatives of the tetrads, which is Cartan’s first equation of structure. In the same limit, the spin-two gauge fields are the spin connection.

**2:00 pm, Tuesday, January 24, 2023
Zoom,
**

Individuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact the Physics Department (phone: 505-277-2616, email: physics@unm.edu) well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact the Physics front office if you need written information in an alternative format.

*A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at http://physics.unm.edu/pandaweb/events/index.php*