List of symbols

\(a,b,c\) Constants in polynomial (§F)
\(a,b,c,d,i\) Coefficients of power law of ABR or OAE (§11.7.3, §17.3.1)
\(a,b,d\) Linear canonical transform (LCT) coefficients (§C)
\(a\) Complex temporal envelope
\(a\) Arbitrary signal (§14)
\(A\) Complex envelope spectrum
\(a_g \) Ideal geometrical image of envelope (§13.2.1)
\(a_n\) Complex temporal envelope in neural domain (§12.2)
\(a_s\) Sampled signal (§14)
\(A_s\) Sampled spectrum (§14)
\(b_n\) Random eigenfunction coefficient (§8.2.6)
\(B\) Bandwidth
\(B_n\) Noise-equivalent bandwidth (§9.4)
\(c\) Wave speed; Speed of light; Speed of sound
\(C\) Circle of confusion (§4)
\(C\) Channel capacity (§5.2.1)
\(C\) Schroeder phase curvature (§12.4.1, §17.3.1)
\(C\) Real part of Fresnel integral (§D)
\(C_T\) Linear canonical transform (LCT) kernel for operator \(T\) (§C)
\(d\) Temporal acuity; Detectable gap (§13.4.4, §15.6, §F)
\(d\) Group-delay dispersion impulse response (§12, §13.2)
\(D\) Aperture size (§4)
\(D\) Group-delay dispersion transfer function (§12, §13.2)
\(D\) Pulse sequence duration (§E)
\(D'\) Pulse sequence duration minus the last pulse duration (§E)
\(D_a\) Acoustic dipole strength (Table §3.1)
\(D_e\) Electromagnetic dipole strength (Table §3.1)
\(\boldsymbol{\mathbf{E}}\) Electric field (vector) (Table §3.1)
\(E\) Electric field (scalar) (§4)
\(ERB\) Equivalent rectangular bandwidth of auditory filter
\(f\) Frequency
\(f\) Focal length (§4)
\(f\) Arbitrary function (§3.2.1)
\(F\) Fourier transform of arbitrary function \(f\) (§3.2.1)
\(\boldsymbol{\mathbf{F}}\) Arbitrary wave field (Table §3.1)
\(f'\) Doppler-shifted frequency (§3.3.3)
\(f'\) Remapped imaged frequency under binaural diplacusis (§17.3.3)
\(f^\#\) F-number (§4.2.1)
\(f_0\) Fundamental frequency
\(f_c\) Carrier frequency
\(f_m\) Modulation frequency
\(f_n\) Cutoff frequency (Figure §9.3)
\(f_T\) Focal time
\(f_{T,gg}\) Focal time estimate of the gerbil and guinea pig time lens
\(f_{T,h}\) Focal time estimate of the human time lens
\(f_s\) Sampling rate
\(f_T^\#\) Temporal imaging f-number (§15.11.1)
\({\cal F}\) Fourier transform
\({\cal F}^{-1}\) Inverse Fourier transform
\(g\) Arbitrary function (§3.2.1)
\(g\) Complex envelope / Mapping function (§5.3.1)
\(g_1,g_2\) Fresnel integral variables (§D)
\(g_T\) Linear canonical transformed (LCT) function (§C)
\(h\) Impulse response function
\(\tilde h \) Impulse response function with reduced coordinate; Point spread function (§13.2.1)
\(\tilde h_d\) Defocused impulse response function for Gaussian pupil (§13.2.2)
\(h_{dr}\) Defocused impulse response function for rectangular pupil (§D)
\(h_L\) Time-lens impulse response function (§10.3, §13.2)
\(\boldsymbol{\mathbf{H}}\) Magnetic field (vector) (Table §3.1)
\(H\) (Shannon's) entropy (§5.2.1)
\(H\) Transfer function
\(H_d\) Amplitude transfer function (ATF) of generalized Gaussian pupil (§13)
\(H_{dr}\) Amplitude transfer function (ATF) of generalized rectangular pupil (§13)
\(H_L\) Time lens transfer function (§10.3)
\({\cal H}\) Hilbert transform (§6)
\({\cal H}^{-1}\) Inverse Hilbert transform (§6)
\({\cal H}\) Optical transfer function (§13)
\({\cal H}_d\) Defocused optical transfer function with Gaussian pupil (§13)
\({\cal H}_{dr}\) Defocused optical transfer function with rectangular pupil (§13)
\(i\) \(\sqrt{-1}\)
\(I\) Intensity
\(I\) Frequency interval (§15.10.1)
\(I_{coh}\) Coherent part of intensity (§8.2.1)
\(I_{inc}\) Incoherent part of intensity (§8.2.1)
\(I_{max}\) Maximum intensity (interference)
\(I_{min}\) Maximum intensity (interference)
\(I_{tot}\) Total intensity (§8.2.1)
\(I_0\) Object intensity (§4)
\(I_1\) Image intensity (§4)
\(I_r\) Intensity (radial) (Table §3.1)
\(I_\theta\) Intensity (azimuth) (Table §3.1)
\(I_\phi\) Intensity (elevation) (Table §3.1)
\(J_n\) Bessel function of the first kind of order \(n\)
\(k\) Wavenumber; Spatial frequency
\(k_x\) Horizontal component of spatial frequency (Table §1.2)
\(k_y\) Vertical component of spatial frequency (Table §1.2)
\(\boldsymbol{\mathbf{k}}\) Wavenumber vector
\(k_c\) Wavenumber at carrier frequency
\(k_i\) Imaginary-part of wavenumber function (absorption) (§3.4.2)
\(k_r\) Real-part of wavenumber function (dispersion) (§3.4.2)
\(K\) Gain (§5.3.1)
\(K\) Stiffness (§11.6.1)
\(K\) Loop gain (§9.3)
\(K_{BM}\) Passive basilar membrane stiffness (§11.6.1)
\(K_f\) Filter DC gain (§9.3)
\(K_m\) Phase detector sensitivity (§9.3)
\(K_v\) Voltage controller oscillator gain (§9.3)
\(l\) Integer
\({\mathscr L}(T) \) Linear canonical transform (LCT) for kernel operator \(T\) (§C)
\(m\) Integer
\(m\) Message (baseband) function (§5.3.1)
\(m\) Modulation depth (audibility, contrast)
\(m\) Frequency slope (chirpiness) (§B.3)
\(M\) Magnification
\(M'\) Complex magnification (defocused system) (§12.2.2)
\(M^*, M_f, M_{f'}, M_{f'}^*\) Distorted magnification under binaural diplacusis (§17.3.3)
\(m_0\) Chirp slope of object (§12.4.1)
\(M_0\) Magnification \(-v/u\)
\(m_1\) Chirp slope of image (§12.4.1)
\(m_r\) Rectangular pulse chirp slope (§B.3)
\(n\) Index of refraction
\(n\) Noise time-signal (§5.3.1)
\(n\) Harmonic number
\(n\) Integer
\(n_k\) Neural group velocity dispersion coefficient (§11.7.3)
\(N\) Noise power (§5.2.1)
\(N\) Number of samples
\(N\) Schroeder phase number of harmonics (§12.4.1)
\(N\) Number of pulses in sequence (§E)
\(NS\) Nonstationarity index (§A.4)
\(p\) Pressure
\(p\) Probability (§5.2.1)
\(P\) Pressure (frequency domain)
\(P\) Pupil function
\({\cal P}\) Cauchy principal value (§6)
\({\cal P}\) Generalized pupil function (§13.2.2)
\(P_e\) Entrance pupil (§14.4.2)
\(P_g\) Gaussian pupil function (§13.2.2)
\(P_r\) Rectangular pupil function (§13.3.2, §D)
\(q,q'\) Linear canonical transform (LCT) variables (§C)
\(Q\) Q-factor of bandpass filter
\(Q_{10}\) Q-factor of bandpass filter at -10 dB points (§11.6.4)
\(Q_{ERB}\) Q-factor of bandpass filter at the ERB bandwidth (§11.6.4)
\(r\) Displacement
\(r\) Received signal time-signal (§5.3.1)
\(r\) Correlation coefficient (Pearson's r)
\(\boldsymbol{\mathbf{r}}\) Position vector
\(r_c\) Critical distance (§8.4.2)
\(R\) Fixed distance (§8.5)
\(R\) Synchronization strength/index (§85)
\(R_{pp}\) Autocorrelation function of \(p\) (§8.2.2)
\(s\) Time lens curvature
\(s\) Time signal
\(s\) Laplace-transform complex frequency (§9.4)
\(s\) Sampler delta function array (comb function) (§14)
\(\hat{s}\) Estimate of time signal (§3.3.3)
\(s_{T,gg}\) Curvature estimate of the gerbil and guinea pig time lens
\(\boldsymbol{\mathbf{S}}\) Poynting vector (Table §3.1)
\(S, S_I\) Intensity/power spectrum
\(S\) Signal power (§5.2.1)
\(S\) Power spectral density / Spectrum (§8)
\(\mathit{S}\) Surface area of room (§8.4.2)
\(S\) Imaginary part of Fresnel integral (§D)
\(S_a\) Amplitude spectrum (§13.3.3)
\(s_h\) Time-lens curvature in humans (§11.6.4)
\(S_\omega\) Acoustic point source strength (Table §3.1)
\(t\) Time
\(t_0\) Gaussian pulse width parameter of the object; Entrance pupil
\(t_1\) Gaussian pulse width parameter of the image; Exit pupil
\(t'\) Complex Gaussian pulse width parameter
\(T\) Period
\(T\) Integration time constant
\(T\) Complex tone standard (§15.11.1)
\(T\) Linear canonical transform (LCT) matrix operator (§C)
\(\tilde T\) Integration variable (§13.2.1)
\(T_{60}\) Reverberation time
\(T_a\) Aperture time
\(T_c\) Carrier period
\(T_s\) Sampling rate period
\(v\) Velocity (§3.3.3)
\(v\) Distance between lens and screen (§4)
\(v\) Neural group-delay dispersion
\(V\) Visibility (§7.2.1, §8)
\(V\) Volume (§8.4.2)
\(V\) Voltage (§11.6.1)
\(v_g\) Group velocity
\(V_c\) Output voltage from loop filter (§9.4)
\(V_d\) Output voltage from phase detector (§9.4)
\(V_i\) Input voltage to phase detector (§9.4)
\(V_o\) Output voltage from voltage controller oscillator (§9.4)
\(v_p\) Phase velocity
\(v_{V-I}\) Neural group-delay dispersion for the segment between wave I and wave V (§11.7.3)
\(u\) Acoustic velocity (Table §3.1)
\(u\) Distance between object and lens (§4)
\(u\) Auditory input (cochlear) group-delay dispersion
\(\boldsymbol{\mathbf{u}}\) Sound velocity (Table §3.1)
\(u_e\) External environment group-delay dispersion (§11)
\(u_o\) Outer-ear group-delay dispersion (§11)
\(u_m\) Middle-ear group-delay dispersion (§11)
\(u_c\) Cochlear group-delay dispersion (§11)
\(w\) Wave energy density (Table §3.1)
\(W\) Cross-spectral density (§8)
\(W_d\) Reciprocal defocus parameter \(=1/u + 1/v + 1/s\) (§13, §F)
\(W_p\) Single pulse duration (§E)
\(x\) x-axis coordinate
\(x\) In-phase modulation (§5.3.1)
\(x\) Real part of analytic signal; arbitrary time signal (§6)
\(x\) Defocus parameter \(=u+sv/(s+v)\) (§12.4.1, §17.3.1)
\(X\) Fourier transform of real part of analytic signal \(X\) (§6)
\(x_0\) Arbitrary spatial position (§3.2.2)
\(y\) y-axis coordinate
\(y\) Quadrature modulation (§5.3.1)
\(x\) Imaginary part of analytic signal (§6)
\(z\) Distance along the z-axis (the optical axis)
\(z\) Analytic signal (§6)
\(X\) Fourier transform of analytic signal \(Z\) (§6)
\(Z_0\) Characteristic impedance (Table §3.1)
\(\alpha,\beta,\gamma\) Direction cosines of wavenumber vector (§4.2.2)
\(\alpha\) Instantaneous phase of complex degree of coherence \(\gamma\) (§8)
\(\alpha\) Total absorption (\(=k_i\)) (§10, §B)
\(\alpha\) Gaussian shape factor (§12.5.3)
\(\alpha'\) Phase-velocity absorption (§B)
\(\alpha”\) Group-velocity absorption (§10, §B)
\(\mathit{\alpha}\) Absorption coefficient (§8.4.2)
\(\beta\) Total dispersion (\(=k_r\)) (§10, §B)
\(\beta'\) Phase-velocity absorption (§10, §B)
\(\beta”\) Group-velocity dispersion (§10, §11, §12, §B)
\(\gamma\) Frequency deviation (§6.5.3)
\(\gamma\) Mutual coherence function (§8)
\(\gamma_{ii} \) Self-coherence function of input signal (§9.5)
\(\gamma_{oo} \) Self-coherence function of output signal (§9.5)
\(\gamma_{io} \) Coherence function between input and output signals (§9.5)
\(\Gamma\) Complex degree of coherence (§8, §9.5)
\(\delta\) Dirac delta function
\(\delta\) Linear phase of coherence function (§8)
\(\delta_{nm}\) Kronecker delta
\(\Delta f\) Spectral bandwidth of narrowband signal
\(\Delta f, \Delta f_{beat}\) Frequency spacing between beating tones (§F)
\(\Delta f, \Delta f_{oct}\) Octave stretch in cents (§15.10.1, §F)
\(\Delta f'\) Iterated octave stretch in cents (§15.10.1)
\(\Delta f_h\) Bandwidth of the time-lens phase modulation in humans (§11.6.4)
\(\Delta k\) Wavenumber difference between beating components (§3.2.1)
\(\Delta l\) Coherence length (§8.2.4)
\(\Delta n\) Path change in index of refraction (§11.6.1)
\(\Delta t\) Deviation from complex tone standard (§15.11.1)
\(\Delta t_{opt}\) Optimal ratio between geometrical and dispersive blurs (Table §12.2, §13.2.2)
\(\Delta \tau\) Coherence time
\(\Delta \omega\) Frequency difference between beating components (§3.2.1)
\(\Delta \omega\) Bandwidth of narrowband signal
\(\Delta \omega\) Phase ramp (§6.3)
\(\Delta \omega\) Phase ramp (§6.3)
\(\dot{\omega}\) Frequency velocity (§6.3)
\(\ddot{\omega}\) Frequency acceleration (§6.3)
\(\epsilon\) Dielectric constant (permittivity) (Table §3.1)
\(\epsilon_0\) Dielectric constant in vacuum (permittivity) (Table §3.1)
\(\zeta\) z-axis coordinate in the traveling pulse coordinate system (§10,§11, §12.2)
\(\zeta\) Damping factor (Figure §9.3)
\(\eta\) Displacement function (§3.3.1)
\(\eta\) Mask coordinate (§4.2.2)
\(\theta\) Azimuth (Table §3.1)
\(\theta\) Angle from optical axis (§4)
\(\theta_{min}\) Angular resolution (§4.2.2)
\(\kappa\) Adiabatic compressibility (Table §3.1)
\(\lambda\) Wavelength
\(\Lambda\) Triangle function
\(\lambda_n\) Eigenvalue (§8.2.6)
\(\mu\) Magnetic permeability (Table §3.1)
\(\mu\) Spectral degree of coherence (§8)
\(\mu_0\) Magnetic permeability in vacuum (Table §3.1)
\(\xi\) Mask coordinate (§4.2.2)
\(\rho\) Fluid density (Table §3.1)
\(\rho_{BM}\) Basilar membrane density per unit length (§11.6.1)
\(\sigma\) Multiplicative factor (§12.4.2, §F)
\(\tau\) Time lag
\(\tau\) Time coordinate in the traveling pulse coordinate system, group delay
\(\tilde\tau_0 \) Reduced coordinate of the object time (§13.2.1)
\(\tau_0\) Initial time of pulse in the traveling pulse coordinate system
\(\tau_1,\tau_2\) Time constants (Figure §9.3)
\(\tau_e\) Effective duration (§8.3.2, §A)
\(\tau_g\) Group delay
\(\tau_p\) Phase delay
\(\varphi\) Phase function (time domain)
\(\phi\) Phase function (frequency domain)
\(\phi\) Elevation (Table §3.1)
\(\phi_e\) Phase error (§9.3)
\(\phi_n\) Schroeder phase for component \(n\) (§12.4.1)
\(\phi_{\Delta f/2}\) Time-lens phase at the cutoff frequencies of \(Q_{10}\) (§11.6.4)
\(\psi\) Field function (§3.2.1)
\(\Psi\) Eigenfunction (§3.3.1, §8.2.6)
\(\omega\) Angular frequency; Modulation frequency
\(\bar{\omega}\) First moment of frequency (§8)
\(\Omega\) Integration domain including radiating source and receivers (§8.2.6)
\(\omega_c\) Carrier angular frequency
\(\omega_{coh}\) Coherent amplitude transfer function cutoff frequency (Gaussian pupil) (§13)
\(\omega_{coh,r}\) Coherent amplitude transfer function cutoff frequency (rectangular pupil) (§13)
\(\omega_H\) Hold-in range (§9.3)
\(\omega_{inc}\) Incoherent modulation transfer function cutoff frequency (Gaussian pupil) (§13)
\(\omega_L\) Lock range (§9.3)
\(\omega_m\) Modulation angular frequency
\(\omega_O\) Pull-out range (§9.3)
\(\omega_P\) Pull-in range (§9.3)