In
physics, extra dimensions are proposed additional
space or
timedimensions beyond the (3 + 1) typical of observed
spacetime, such as the first attempts based on the
Kaluza–Klein theory. Among theories proposing extra dimensions are:[1]
Universal extra dimension, proposed and first studied in 2000, assume, at variance with the ADD and RS approaches, that all fields propagate universally in extra dimensions.
Multiple time dimensions, i.e. the possibility that there might be more than one dimension of
time, has occasionally been discussed in physics and philosophy, although those models have to deal with the problem of
causality.
^For a pedagogical introduction, see M. Shifman (2009). Large Extra Dimensions: Becoming acquainted with an alternative paradigm. Crossing the boundaries: Gauge dynamics at strong coupling. Singapore: World Scientific.
arXiv:0907.3074.
Bibcode:
2010IJMPA..25..199S.
doi:
10.1142/S0217751X10048548.
In
physics, extra dimensions are proposed additional
space or
timedimensions beyond the (3 + 1) typical of observed
spacetime, such as the first attempts based on the
Kaluza–Klein theory. Among theories proposing extra dimensions are:[1]
Universal extra dimension, proposed and first studied in 2000, assume, at variance with the ADD and RS approaches, that all fields propagate universally in extra dimensions.
Multiple time dimensions, i.e. the possibility that there might be more than one dimension of
time, has occasionally been discussed in physics and philosophy, although those models have to deal with the problem of
causality.
^For a pedagogical introduction, see M. Shifman (2009). Large Extra Dimensions: Becoming acquainted with an alternative paradigm. Crossing the boundaries: Gauge dynamics at strong coupling. Singapore: World Scientific.
arXiv:0907.3074.
Bibcode:
2010IJMPA..25..199S.
doi:
10.1142/S0217751X10048548.