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SUMMARY:Inflatinary Cosmology as a Precision Test of Quantum Mechanics
DTSTART;VALUE=DATE-TIME:20190730T183600Z
DTEND;VALUE=DATE-TIME:20190730T185400Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460182@indico.cern.ch
DESCRIPTION:Speakers: Carl Rosenzweig (Syracuse University)\nInflation pre
dicts that quantum fluctuations determine the large scale structure of the
Universe. This raises the striking possibility that quantum mechanics\, d
eveloped to describe nature at short distances\, can be tested by studying
nature at its most immense -- cosmology. By fully accepting the inflation
ary paradigm we realize this possibility. A nonlinear generalization of q
uantum mechanics modifies predictions for the cosmological power spectrum.
Observational cosmology is sufficiently precise to place a stringent limi
t\, $b\\leq 3\\times 10^{-34}$ eV\, on the size of the nonlinear term.\n\n
https://indico.cern.ch/event/782953/contributions/3460182/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460182/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inflation\, dark energy and dark matter in supergravity
DTSTART;VALUE=DATE-TIME:20190730T185400Z
DTEND;VALUE=DATE-TIME:20190730T191200Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460115@indico.cern.ch
DESCRIPTION:Speakers: Sergei V. Ketov (Tokyo Metropolitan University and K
ali IPMU)\nA theoretical description of cosmological inflation\, \ndark en
ergy (cosmological constant) and dark\nmatter in supergravity is non-trivi
al. I review the\nstandard procedures and propose the new ones\nbased on r
ecent developments in supergravity theory. \nPhenomenological aspects of d
ark matter in high-scale SUSY \nbreaking scenario are also briefly discuss
ed.\n\nP.S. Based on recent publications of myself with collaborators\,\ns
ee http://inspirehep.net/search?p=find+a+ketov\nP.P.S. My talk may be also
suitable for Field Theory & String Theory\n\nhttps://indico.cern.ch/event
/782953/contributions/3460115/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460115/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Upcoming large-scale structure cosmology results from the Dark Ene
rgy Survey Year 3
DTSTART;VALUE=DATE-TIME:20190730T210000Z
DTEND;VALUE=DATE-TIME:20190730T213000Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460119@indico.cern.ch
DESCRIPTION:Speakers: Jack Elvin-Poole (The Ohio State University)\nThe Da
rk Energy Survey (DES) has provided world leading measurements in multiple
probes of the late time universe. Using probes of weak gravitational lens
ing\, galaxy clustering\, cluster cosmology and supernovae from the first
year of observations\, DES was able test the Lambda CDM model with greater
constraining power than any other individual galaxy survey. I will presen
t the latest updates from the upcoming DES Year 3 large scale structure co
smology results\, which use an observed area three times that of Year 1. W
ith greater statistical power\, a number of analysis improvements have bee
n implemented including to photometric redshifts\, observational systemati
c mitigation\, and astrophysical systematic modelling. DES Year 3 will pro
vide one of the most robust tests of the potential tensions in clustering
amplitude between the late and early universe using the combination of gal
axy clustering and weak gravitational lensing. We also forecast a 2-3% mea
surement of the angular diameter distance at redshift of 1 from measuremen
ts of the Baryon Acoustic Oscillation scale. The DES results and analysis
techniques will pave the way for the next generation of large scale struct
ure cosmology experiments such as LSST and DESI.\n\nhttps://indico.cern.ch
/event/782953/contributions/3460119/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460119/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inhomogeneous Initial Conditions and the Start of Inflation
DTSTART;VALUE=DATE-TIME:20190730T180000Z
DTEND;VALUE=DATE-TIME:20190730T181800Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460128@indico.cern.ch
DESCRIPTION:Speakers: Patrick Fitzpatrick (Massachusetts Institute of Tech
nology)\nThe robustness of inflation to inhomogeneous initial conditions f
or matter fields and the spacetime metric is under investigation. If infla
tionary expansion fails to begin under sufficiently inhomogeneous initial
conditions\, such that inflation requires fine-tuning of its initial state
to occur\, then its naturalness is challenged. I will present results for
the range of initial conditions which give rise to inflation\, based on n
umerical calculations which evolve the equations of motion of the scale fa
ctor and the inflaton field coupled to its quantum fluctuations and metric
perturbations through a well-defined set of nonlinear interactions in the
Hartree approximation. These results address to what extent inflation can
occur under inhomogeneous initial conditions for a few standard slow-roll
single-field inflationary models\, in calculations which include effects
of back-reaction of perturbations on the background dynamics and on the pe
rturbations themselves\, and which have wide applications beyond the infla
tionary models I will present. We have found that significantly inhomogene
ous initial conditions can have nontrivial effects on the number of efolds
of inflation. In particular\, the initial inhomogeneities can shift the r
egions of phase space that support sufficient inflation\, compared to the
case in which one neglects all perturbations. But we also find that there
seems to be no reduction in the overall volume of phase space that yields
sufficient inflation\, thereby providing an interesting measure of robustn
ess. Our findings are consistent with recent simulations involving full (3
+1) numerical relativity. However\, by relying on certain well-studied app
roximations\, our numerical approach can be applied more efficiently to a
wide range of models\, and can track the evolution of perturbations across
a wide range of scales\, thereby complementing the recent numerical-relat
ivity simulations.\n\nhttps://indico.cern.ch/event/782953/contributions/34
60128/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460128/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Enhancing Dark Energy Constraints from Redshift-Space Galaxy Clust
ering
DTSTART;VALUE=DATE-TIME:20190730T203000Z
DTEND;VALUE=DATE-TIME:20190730T210000Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460145@indico.cern.ch
DESCRIPTION:Speakers: ZHENG ZHENG (University of Utah)\nGalaxy clustering
from ongoing and forthcoming large galaxy surveys plays an important role
in understanding the acclerated cosmic expansion\, through the measurement
s of baryon acoustic oscillations (BAO) and the redhshift-space distortion
s (RSD). The latter can be used to infer the linear structure growth rate
in the universe\, which can constrain the equation of state of dark energy
and test theories of gravity. Current constraints on the growth rate main
ly comes from large-scale RSD\, while the intermediate- and small-scale RS
D with high statistical power is not used because of model challenges. I w
ill present a method based on high-resolution N-body simulations to accura
tely model redshift-space galaxy clustering and efficiently explore the pa
rameter space. I will then discuss how systematic effects in relating gala
xies to dark matter field could affect our ability to constrain the struct
ure growth rate. I will convey the encouraging message that the intermedia
te- and small-scale RSD will substantially tighten the constraints on the
growth rate and help better constrain dark energy or test theories of grav
ity.\n\nhttps://indico.cern.ch/event/782953/contributions/3460145/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460145/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dark Energy as a New Base Energy Tier
DTSTART;VALUE=DATE-TIME:20190730T191200Z
DTEND;VALUE=DATE-TIME:20190730T193000Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460185@indico.cern.ch
DESCRIPTION:Speakers: Scott Gordon (University of Central Florida)\nThe fi
eld of physics has been built on the scientific method where our greatest
theories have been developed from a well-established foundation. However\
, so far\, no derivations stemming from our current mathematics expressing
our most validated theories has been able to reveal the nature of “dark
” energy. It may be time to consider... What if it is impossible to der
ive the nature of dark energy by using our current foundational mathematic
s expressing our current theories? What if a new model of the universe is
required\; a more fundamental model to which a new "primordial" math is r
equired? A model that starts with only one ingredient and its associated
energy as the only way to reveal the nature of dark energy? Such a basic
elementary model would have to be derived independently from our current m
athematics and yet provide a new foundation from which to derive our curre
nt validated theories. If successful\, the new math associated with this
more fundamental model will define dark energy which could then be used to
reveal the role dark energy plays in energy fields\, gravity\, general re
lativity\, and much more.\n\nhttps://indico.cern.ch/event/782953/contribut
ions/3460185/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460185/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Coherent Enhancement of the Axion Decay Constant in Inflation and
the Weak Gravity Conjecture
DTSTART;VALUE=DATE-TIME:20190730T181800Z
DTEND;VALUE=DATE-TIME:20190730T183600Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460136@indico.cern.ch
DESCRIPTION:Speakers: Maksim Piskunov (Northeastern University)\nModels of
axion inflation based on a single cosine potential require the axion deca
y constant to be super-Planckian in size. However\, a super-Planckian axio
n decay constant is disfavored in quantum gravity and in strings\, and by
the weak gravity conjecture. Here we propose a coherent enhancement mechan
ism which can produce an effective axion decay constant which is super Pla
nckian even if the true decay constant is sub Planckian. We discuss the ut
ility of this mechanism for a variety of axion potentials originating in s
upersymmetry\, supergravity\, and strings. The coherent enhancement mechan
ism allows one to reduce an inflation model with an arbitrary potential to
an effective model of natural inflation\, i.e. with a single cosine\, by
expanding the potential near an inflationary point\, and matching the expa
nsion coefficients to those of natural inflation. We demonstrate that this
approach can predict the number of e-foldings in a given inflation model
without the need for numerical simulation. Further we show that the effect
ive decay constant $f_e$ can be directly related to the spectral indices s
o that $f_e = M_\\text{P} / \\sqrt{1 - n_s - r / 4}$ where $n_s$ is the sp
ectral index for curvature perturbations and $r$ is the ratio of the power
spectrum of tensor perturbations and curvature perturbations. The current
data on $n_s$ and $r$ constrains the effective axion decay constant so th
at $4.9 \\leq f_e / M_\\text{P} \\leq 10.0$ at $95\\%$ CL. Thus an importa
nt result of the analysis is that the effective axion decay constant has a
n upper limit of $\\sim 10 M_\\text{P}$ in units of Planck mass in axion c
osmology for any potential-based model which produces successful inflation
. The coherent enhancement mechanism for the generation of an effective $f
_e > M_\\text{P}$ while the true axion decay constant $f M_\\text{P}$ and
the true axion decay constant $f \n\nhttps://indico.cern.ch/event/782953/
contributions/3460136/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460136/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constraining Temporal Oscillations of Cosmological Parameters Usin
g Type Ia Supernovae
DTSTART;VALUE=DATE-TIME:20190730T200000Z
DTEND;VALUE=DATE-TIME:20190730T203000Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460151@indico.cern.ch
DESCRIPTION:Speakers: Sasha Brownsberger (Harvard University)\nThe existin
g set of type Ia supernovae (SNe Ia) is now sufficient to detect oscillato
ry deviations from the canonical $\\Lambda$CDM cosmology. \nWe determine t
hat the Fourier spectrum of the Pantheon data set of spectroscopically wel
l-observed SNe Ia is consistent with the predictions of $\\Lambda$CDM. \n
We also develop and describe two complementary techniques for using SNe Ia
to constrain those alternate cosmological models that predict deviations
from $\\Lambda$CDM that are oscillatory in conformal time. \nThe first tec
hnique uses the reduced $\\chi^2$ statistic to determine the likelihood th
at the observed data would result from a given model. \nThe second techni
que uses bootstrap analysis to determine the likelihood that the Fourier s
pectrum of a proposed model could result from statistical fluctuations aro
und $\\Lambda$CDM. \nWe constrain three oscillatory alternate cosmological
models: one in which the dark energy equation of state parameter oscillat
es around the canonical value of $w_{\\Lambda} = -1$\, one in which the en
ergy density of dark energy oscillates around its $\\Lambda$CDM value\, an
d one in which gravity derives from a scalar field evolving under an oscil
latory coupling.\nWe further determine that any alternate cosmological mod
el that produces distance modulus residuals with a Fourier amplitude of $\
\simeq 36$ millimags is strongly ruled out\, given the existing data\, for
frequencies between $\\simeq 0.08\\ \\textrm{Gyr}^ {-1} h_{100}$ and $\\s
imeq 80\\ \\textrm{Gyr}^ {-1} h_{100}$.\n\nhttps://indico.cern.ch/event/78
2953/contributions/3460151/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460151/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Weak-Lensing Mass Calibration of $\\mu_{\\star}$ at High Redshifts
with the Dark Energy Survey Year 1
DTSTART;VALUE=DATE-TIME:20190730T213000Z
DTEND;VALUE=DATE-TIME:20190730T220000Z
DTSTAMP;VALUE=DATE-TIME:20210115T162405Z
UID:indico-contribution-302474-3460184@indico.cern.ch
DESCRIPTION:Speakers: Maria Elidaiana da Silva Pereira (Brandeis Universit
y)\nGalaxy clusters have been established as an important tool to study th
e matter distribution\, the formation and evolution of the structures in t
he Universe with great potential to be one of the most powerful cosmologic
al probes. To achieve this\, we need to understand the systematics involve
d in the cluster mass calibration\, which is the current dominating source
of uncertainties for using clusters to probe cosmology. Observationally\,
we can not assess the true mass of galaxy clusters\, but we can rank them
by some proxy for the mass. We can define a mass proxy by looking for dif
ferent observables in the clusters. A good proxy should have a linear rela
tion with the total mass of the cluster and low scatter in comparison to s
ome observable. To meet these requirements\, we proposed $\\mu_{\\star}$\,
a physically motivated cluster mass-proxy proportional to the total stell
ar mass of red and blue members\, that is independent of the formation his
tory of the red sequence and has a low scatter with the X-ray temperature
relation (Palmese et al. 2019). We use redMaPPer galaxy clusters identifie
d in the Dark Energy Survey Year 1 data for reliable calibration of $\\mu_
{\\star}$ at high redshifts. In a blinded analysis\, we perform the mass-c
alibration of $\\mu_{\\star}$ using $\\sim 6\,000$ clusters split into 12
subsets spanning in the ranges of $0.1 \\leq z\n\nhttps://indico.cern.ch/e
vent/782953/contributions/3460184/
LOCATION:Northeastern University West Village G 106
URL:https://indico.cern.ch/event/782953/contributions/3460184/
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