Inflación y Polarización de la Radiación Cósmica de Fondo

CMBPolDetectando inflacion con las

Polarizaciones de la RCF

Yohana Bonilla

Profesor:Cesar A. Valenzuela Toledo

Universidad del Valle

Jun/19/2011

Y. Bonilla (UniValle) CMBPol Jun/19/2011 1 / 14

Contenido

1 Cosmologıa de precisionIntroduccion

2 Observables cosmologicosCosmologıa de concordancia

3 Cosmologıa inflacionariaInflacion-Big BangLa fısica de la inflacionObservables cosmologicos

Perturbaciones escalaresPerturbaciones vectorialesPerturbaciones tensoriales

4 Polarizaciones de la RCF: Prueba unica del Universo Temprano


Cosmologıa de precision Introduccion

Introduccion


Observables cosmologicos Cosmologıa de concordancia

Cosmologıa de concordancia

Conjunto mınimo de parametros cuyos valores medidos caracterizan eluniverso observado.

Modelo de seis parametros? Ωb,ΩCDM, h, τ: fondo homogeneo.? As, ns: fluctuaciones de densidad primordiales





Modelo de seis parametros? Ωb,ΩCDM, h, τ: fondo homogeneo.

? As, ns: fluctuaciones de densidad primordiales





Modelo de seis parametros? Ωb,ΩCDM, h, τ: fondo homogeneo.? As, ns: fluctuaciones de densidad primordiales



Figura: Parametros del modelo de la cosmologıa de concordancia. Asumimos un universo planoi.e. Ωb + ΩCDM + ΩΛ ≡ 1; en caso contrario se incluye la contribucion de curvatura Ωk . h describe la velocidad de

expansion del universo actual, H0 = 100h km s−1 Mpc−1. “Espectro” se refiere a las perturbaciones de densidad o escalares

primordiales, parametrizadas por As(k/k?)ns−1, donde k? = 0,002 Mpc−1 es una escala especıfica.



Label Definition Physical OriginΩk Curvature Initial Conditions

Σmν Neutrino Mass Beyond-SM Physicsw Dark Energy Equation of State UnknownNν Neutrino-like Species Beyond-SM PhysicsYHe Helium Fraction Nucleosynthesisαs Scalar “Running” InflationAt Tensor Amplitude Inflationnt Tensor Index InflationfNL Non-Gaussianity Inflation (?)S Isocurvature InflationGµ Topological Defects Phase Transition

Cuadro: Parameters in possible future concordance cosmologies are summarized. At present, these numbers are all eitherconsistent with zero (or −1 in the case of w), or are fixed independently of a fit to the global cosmological dataset, in the caseof the helium fraction and the number of neutrino species. The tensor or gravitational wave spectrum is conventionally taken tobe of the form At(k/k?)nt . One could extend the parameterization of the dark energy to include a non-trivial equation ofstate (w′), while the parameterization of the scalar spectrum could incorporate more general scale-dependence, such as“features” in the spectrum. Likewise, fNL is a placeholder for measurements of generic non-Gaussianity (see §??) and theparameter S quantifies the amplitude of an isocurvature contribution to the scalar spectrum (see §??).



Label Definition Physical Origin Current Status SectionAs Scalar Amplitude V, V ′ (2,445± 0,096)× 10−9 §??

ns Scalar Index V ′, V ′′ 0,960± 0,013 §??αs Scalar Running V ′, V ′′, V ′′′ only upper limits §??At Tensor Amplitude V (Energy Scale) only upper limits §??nt Tensor Index V ′ only upper limits §??r Tensor-to-Scalar Ratio V ′ only upper limits §??

Ωk Curvature Initial Conditions only upper limits §??fNL Non-Gaussianity Non-Slow-Roll, Multi-Field only upper limits §??S Isocurvature Multi-Field only upper limits §??Gµ Topological Defects End of Inflation only upper limits §??

Cuadro: The inflationary parameter space, i.e. the set of cosmologicalobservables which are directly associated with inflation. Under “physical origin”V ,V ′, etc. refer to the derivative(s) of the potential to which this variable is mostsensitive. A detailed discussion of the connection between inflationary physics andthe corresponding observable can be found in the listed subsections.


Cosmologıa inflacionaria Inflacion-Big Bang

Inflacion como una solucion a los problemas delBig-Bang

1 Problema de las reliquias no deseadas.

2 Problema de planitud.

3 El problema de horizonte.


Cosmologıa inflacionaria Fısica de la inflacion

La fısica de la inflacion

¿Que controla la expansion acelerada del Universo temprano?

Ecuaciones de Friedmann, factor de escala a(t)

H2 =

(a

a

)2

=1

3M2pl

ρ, (1)

H +H2 =a

a= − 1

6M2pl

(ρ+ 3p) (2)

of a spatially flat universe with Friedmann-Robertson-Walker (FRW) metric1

ds2 = −dt2 + a(t)2dx2 (3)

1For simplicity, we anticipate the inflationary solution of the flatness problem andassume that the spatial geometry is flat. The generalization to curved space isstraightforward.


Cosmologıa inflacionaria Fısica de la inflacion

reheating

Figura: Examples of Inflaton Potentials. Acceleration occurs when the potential energy of the field V dominates over its

kinetic energy 12φ2. Inflation ends at φend when the slow-roll conditions are violated, ε→ 1. CMB fluctuations are created by

quantum fluctuations δφ about 60 e-folds before the end of inflation. At reheating, the energy density of the inflaton isconverted into radiation.Left: A typical small-field potential. Right: A typical large-field potential.


Cosmologıa inflacionaria Observables cosmologicos

Perturbaciones escalares



Perturbaciones vectoriales



Perturbaciones tensoriales (Ondas Gravitacionales)


Polarizaciones de la RCF

Perturbaciones vectoriales

QuadrupoleAnisotropy

Thomson Scattering

e–

Linear Polarization

COLD

HOT

Figura: Thomson scattering of radiation with a quadrupole anisotropy generates linear polarization [?]. Red colors (thicklines) represent hot radiation, and blue colors (thin lines) cold radiation.


Inflación y Polarización de la Radiación Cósmica de Fondo

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