Talk Title and Abstract:
Cosmological
results
from
the
complete
eBOSS
survey
From
2009
to
2019,
the
Baryon
Oscillation
Spectroscopic
Survey
(BOSS)
and
its
extension
eBOSS
used
the
SDSS
telescope
to
obtain
precise
redshifts
for
millions
of
galaxies
and
quasars.
From
the
distribution
of
these
objects
we
were
able
to
get
very
accurate
measurements
of
the
Baryon
Acoustic
Oscillations
(BAO)
scale
from
redshift
0.2
to
redshift
1.5.
At
the
same
time,
BOSS
and
eBOSS
obtained
optical
spectra
of
over
210
000
high
redshift
quasars
(z>2.15)
with
the
goal
of
detecting
the
BAO
feature
in
the
clustering
of
the
intergalactic
medium,
using
a
phenomenon
known
as
the
Lyman
alpha
forest
(LyaF).
In
this
talk
I
will
overview
the
final
results
from
the
LyaF
dataset
of
eBOSS,
including
a
1.4%
measurement
of
the
BAO
scale
at
z=2.33
presented
in
du
Mas
des
Bourboux
et
al.
(2020).
In the second part of the talk I will discuss the cosmological implications of the BAO measurements from BOSS/eBOSS, presented in Alam et al. (2020). This is the most comprehensive study of the expansion history of the Universe during its last 11 billion years. and it allows a detailed analysis of the spatial curvature of the Universe, the abundance of Dark Energy, the sum of the neutrino masses, and a new look at the infamous tension in the measurements of the Hubble constant.
Finally, I will also give an update on the status of the Dark Energy Spectroscopic Instrument (DESI). In the next few years DESI will increase the current spectroscopic dataset by an order of magnitude. It will provide an exquisite measurement of the expansion over cosmic time, while at the same time addressing other interesting questions: the sum of the mass of the neutrino species, properties of dark matter particles, tests of general relativity and the shape of the primordial power spectrum of density fluctuations.
Would you like to join this Zoom seminar? Please email Donna Hayes.